Light Metals 2023

The Minerals, Metals & Materials Society (TMS) classically serves as an intersection point of academia and industry, giving experts opportunities to expand their expertise while simultaneously helping other experts expand their own expertise in kind. It is a complexly intertwined yet beneficial set of relationships that supports technology transfer, that improves or reinvents the state of the artState-of-the-Art, and that thrives on collegiality. Via his volunteer work through TMS, Professor Barry WelchBarry Welch has consistently and tirelessly exemplified all of these qualities and has routinely and positively influenced the work and workforce of the worldwide aluminumAluminum industry. This paper presents personal reflections on some specific instances of Prof. Welch’s volunteer activities that have made TMS a better professional society and that have elevated the field and the good of the order in the process.

Barry WelchBarry Welch is well recognized for his contribution to advancing the science and practice of smelting AluminaAlumina to AluminiumAluminium Metal. He has also made a significant contribution to advancing anodeAnode technology, in particular through the work of his students. This is explored further in an accompanying paper. What is probably less well recognized are the significant challengesChallenges and opportunities Barry has laid out to anodeAnode producers to improve anode qualityAnode quality to meet the increasingly stringent requirements of the Potlines customer. These challengesChallenges and opportunities will be outlined and their potential impact described.

By building on the scientific and practical knowledge outstanding smelting cell designsDesign have been developed that are energy efficient and environmentally responsible. With constraints arising from regional availability of energy and the substantial cost of supporting infrastructure, capacity creepCapacity creep by increasing amperage on the installed capacity provides a path for satisfying the growth in demand for the metal. Invariably designDesign and operating retrofits become desirable or necessary because of cell heat balance and other constraints and these can lead to adverse performance and operating characteristics, such as a substantial reductionReduction in cell life or reduced efficienciesEfficiency. Root-casue contributors to such undesireable consequences are spatial and temporal changes of necessary transfer processes—the physics of getting the consumables or energy to or from the reacting sites at the rate required in order to maintain the desired uniformity in the cell. Hitherto this has been ignored—avoiding or minimising is the next challengeChallenges.

Barry WelchBarry Welch has a longLong history of supporting carbon anodeCarbon anode research from the perspective of both the anodeAnode producer and the potroom customer. The outcomes of this research from Barry and his students continue to be essential reading for anodeAnode producers and technologists. The key learnings of the research will be summarised to provide a single entry point to the huge body of work that has been produced, to remind experienced technologists of the source of the work and to inspire new scientists and engineers to explore the world of anode carbonAnode carbon.

In February 2019, Boyne Smelters Limited (BSL) establishedEstablished a project team to recover ReductionReduction Line 3 from a process excursion. The Line 3 operationOperations had deteriorated progressively through 2018, with increasing levels of cell instability, anodeAnode spiking, and work handed over between shifts had reached critical levels. By January 2019, average current efficiencyCurrent efficiency had dropped to 91.7% and power efficiencyPower efficiency had climbed to 13.45 DCkWhr/kg Al. The recoveryRecovery project ran for 2 months and quickly achieved stable operationOperations through a series of project clusters targeting exception cell recoveryRecovery, new cell control, and management of intergenerational cell designsDesign. An average of 64 mV was saved in 2019 compared to 2018, representing a power efficiencyPower efficiency improvementImprovement of 0.24 DCkWhr/kg Al. Further stabilisation into 2020 resulted in full-year performance of 94.2% and 12.96 DCkWhr/kg Al current efficiencyCurrent efficiency and power efficiencyPower efficiency respectively. This paper describes the fundamental approach taken to problemProblems-solve and deliver value quickly.

This paper discusses a new individual anode current measurementIndividual anode current measurement scheme and its applications in real-timeReal-time monitoring and control of the Hall-HéroultHall-Héroult process. While anodeAnode current can be directly measured from the anodeAnode rod, this approach takes measurementsMeasurement from the anodeAnode beam allowing the sensors to remain intact through various cell operationsOperations, including anode changeAnode change. This instrumentation scheme employs smart sensors that are daisy-chained on a common bus for digital data transfer. This approach limits electromagnetic interferences and offers system self-configuration and self-diagnosis, thus allowing for easy maintenance. The system can be configured to work across a broad range of cell technologies. Monitoring anodeAnode current distributionsCurrent distribution helps improve process operationOperations and allows early detection of process faults such as perfluorocarbonPerfluorocarbon (PFC) co-evolution and blocked feedersFeeder. This also offers the ability to monitor process states such as local aluminaAlumina concentration and bath temperature, along with potential improvementsImprovement to cell operationOperations and current efficiencyCurrent efficiency.

The UniversityUniversities of Auckland has had a more than 40-year history of research contributions supporting the light metals industries. This research programme was initiated with the appointment of Professor Barry WelchBarry Welch in Chemical and Materials Engineering but subsequently broadened to embrace academics across a range of disciplines, particularly in chemical sciences. Work was initially focused on the aluminiumAluminium and aluminaAlumina industries but has extended at times into lithium, magnesium and titaniumTitanium. A defining characteristic of this work has always been close engagementEngagement with the light metals industries. However, over time, the nature of this interactionInteractions has evolved. Of note has been convergence on a range of industry-defining and challenging issues where cross-sector collaborations, often working closely with government agencies, have progressively displaced individual projects addressing technical advantage. Environmental footprint and response to a dynamic energy environmentEnvironment are prominent within this common ground. These trends will be examined along with potential future directions for this research relationship.

Aluminium reductionAluminium reduction requires aluminaAlumina to be fed and dissolved into electrolyte. The feeder holeFeeder hole condition may impact severely the ability to dissolve the added aluminaAlumina. In this study, two sets of observations were made on a large sample of aluminium reductionAluminium reduction cells to understand the feeder hole condition progress during feed events and determine which reductionReduction cell parametersCell parameters affect the feeder holeFeeder hole condition and the progression pathway of the feeding event sequence. The results show that feed rateFeed rate has a major impact on the initial feeder hole condition and is determinant to the pathway of the feeding sequence. Higher superheatSuperheat, lower excess AlF3 and longer time since the last anode changeAnode change increased the probability of finding feeder hole conditions conducive to dissolutionDissolution. The observations of blocked feeder holesFeeder hole were found to be linked to abnormal process conditions or a mechanical issue. Changes made to the feeding strategyStrategy between the two observation sets led to a significant improvementImprovement of the feeder holeFeeder hole condition. The proportion of opened feeder holes increased from 12 to 41%, resulting in a more than 50% reductionReduction of the anode effectAnode effect frequency smelter-wide over an 18 month period.

The cell top chamber is an important region for exchanging material and energy with the bath and the surrounding environmentEnvironment. A considerable heat loss of the aluminium smeltingAluminium smelting cells is lost through this space. The heat transferHeat transfer behaviour in the cell top is complex—ambient air and gases generated in the bath enter the cell top, undergo chemical reactions, and are finally collected by the exhaustExhaust duct. This paper presents a dynamic coupled mass and thermal model for the top chamber of the aluminium smeltingAluminium smelting cell. Based on the model, the dynamics of cell top temperature under different operationsOperations are studied. This model can be used to investigate the influence of cell operationsOperations on the cell top heat balance, especially during power modulation.

The rate of alumina dissolutionAlumina dissolution in cryolitic meltsMelt is critical for the management of aluminiumAluminium production pots. The kinetics of the dissolutionDissolution reaction depends on the combined effects of physical and chemical characteristics of aluminaAlumina. The literature mentions several methods to follow the rate of dissolutionDissolution, with variable degrees of complexity and success. We report a combination of analytical tools to evaluate the dissolutionDissolution rates of various industrial aluminasAlumina in an industrial cryoliteCryolite bath collected shortly before the anodeAnode effect. Batches of powders were sequentially added to an electrochemical cell specifically designed for this test. The dissolutionDissolution rate was measured electrochemically, and an automatic script was developed to measure the flotation time of the alumina raftsAlumina rafts from digital recordings. We correlate the alumina dissolutionAlumina dissolution rate and flotation times, with the initial characteristics of the aluminaAlumina powder.

Carbon anodesCarbon anode in Hall-HéroultHall-Héroult cells are consumed continuously and changed periodically. The anode changeAnode change operationOperations introduces a major energy deficit which adversely perturbs the mass and heat balance of the cell. The freeze that formed underneath the newly replaced anodesAnode impedes normal bath circulation and mixing, removes local heat as it dissolves, and disrupts the normal anodeAnode current flow which deforms the metal pad via magnetohydrodynamicMagnetohydrodynamic (MHD) forces. These may lead to increased process faults and loss of process efficiencyEfficiency. This paper proposes the use of individual anode current measurementsIndividual anode current measurement to monitor the cell conditions and the dissolutionDissolution of anodeAnode freeze in real timeReal-time. This helps to return the cell to nominal operationOperations conditions quickly, by identifying issues such as low local superheatSuperheat, along with providing information to enable further improvementsImprovement to operational procedures such as ACD adjustments for new anodesAnode. This improves process and energy efficienciesEfficiency following anode changeAnode change operationsOperations.

Artificial IntelligenceArtificial Intelligence has the potential to generate significant value and unlock numerous business opportunities while supporting Emirates Global AluminiumAluminium’s (EGA) strategic ambitions and values of innovation and continuous improvementContinuous improvement. In order to build a high performing machine learningMachine learning model we need to fuel it with a large amount of quality data. Based on an initial survey done to determine our paper consumption within the Potlines, we have approximately 1.6 million sheets of paper consumed annually in ReductionReduction. This is where Smart Assistance and Quick Response (SAQR)Smart Assistance & Quick Response (SAQR)—an advanced mobile applicationMobile Application can unlock new value via digitization, automationAutomation and enable future AI implementation. The SAQRSmart Assistance & Quick Response (SAQR) application is expected to enhance EGA’s data collection, increase overall accuracy and provide transparent tracking throughout our operationsOperations, enabling faster decision making. The team behind SAQR is now focused on extending its reach within EGA. SAQRSmart Assistance & Quick Response (SAQR) is currently being used in potlines, crucible tracking, reductionReduction process controlProcess control and busbarBusbar monitoring. Today we have full visibility of every crucible journey within EGA and in the future we aspire to have full visibility of every process, action, and activity within the entire production chain.

For years, Barry WelchBarry Welch has been promoting the idea of designing wider cells. Preliminary modellingModelling work (Dupuis and Welch in Aluminium 93:45–49, 2017; Dupuis in Proceedings of the 37th international ICSOBA conference, 2019, 849–859) already demonstrated some of the advantages of using wider cells like reducing the external potshell area per electrolysisElectrolysis area ratio that helps the designDesign of low energy consumption cells and reducing the potshell length to width ratio that helps designing even higher amperage cells without further increasing the potroom width and the crane span. A third advantage is to help reduceReduce the formation of dissolved aluminaAlumina concentration gradient in the bath by allowing the addition of two new alumina feedingAlumina feeding channels. The MHDMagnetohydrodynamic (MHD) cell stability code MHDMagnetohydrodynamic (MHD)-Valdis including its alumina dissolutionAlumina dissolution module has been used to study the impact of the addition of two extra longitudinal feeding channels in order to use three channels to feed aluminaAlumina into the cell. Results obtained will be presented.

In this paper, we extend the pragmatic modelPragmatic model for alumina feeding, presented in Johansen et al. Light metals 2022, to treat the associated evolution of bath temperature. The underlying idea of the framework is to reduceReduce its computational overhead to allow for very fast simulationSimulation of the dissolved alumina, particle alumina, and bath temperature evolution within aluminium reductionAluminium reduction cells. Two main advances presented in this work: (1) a generic method to read velocity data from any CFD simulation to the pragmatic modelPragmatic model and (2) inclusionInclusions of governing equation to simulate the bath temperature evolution. The physics associated with the various heat loss modes from the bath as well as theSolubility temperature dependence of the alumina solubility in the bath is represented in the model. The demonstration cases discussed in this work show that the proposed framework runs much faster than real timeReal-time (up to 75 times). The average bath and metal temperature in the demonstration case is observed to depend on the feeding pattern used to add alumina into the bath. The proposed framework can be used to observe the spatial and temporal changes of dissolved and particle alumina as well as the bath temperature within a cell.

The heat balance of an Aluminum Electrolysis Cell (AEC) representsAluminum electrolysis a very sensitive aspect of its operationOperations. Steady-state heat balance is quite well understood, thanks to industrial expertise and widely used steady-state finite elements models. With the increasing interest in power modulation, these tools become insufficient to predict the time-dependent heat balance of the cell. Above all, they are not suited to predict the melting or formation of the side ledgeSide ledge, a protective solid layer formed on the cell to avoid the corrosive action of the liquid electrolytic bath on the sidewalls. The authors developed a new thermal–electrical model coupling ANSYS® Mechanical software and Python, able to compute the transient heat balance of an AEC, including thePhase change phase changePhase change dynamic of the side ledgeSide ledge and thermal contact resistance. It has been found to give both accurate results and improved computational time, which becomes a crucial aspect for transient simulationsSimulation of such complex and heavy models.

Anode changeAnode change is the most important operationOperations in aluminum electrolysisAluminum electrolysis industry. Influence of new anodesAnode is mainly concentrated in two aspects: thermal impact and magneto-hydrodynamic (MHDMagnetohydrodynamic (MHD)) impact. This paper only focuses on the thermal impact part. The paper theoretically calculates the heat required of new anodesAnode and heat generation of the anode set modifierAnode set modifier, heat release of metal/bath temperature decrease and electrolyte solidificationSolidification. There may be a lack of more than 50% of energy or heat during the process of anode changeAnode change. The anode changeAnode change in one pot has an individualized characteristic. There are some ‘sensitive anodes‘Sensitive anodes’’ with smaller anodeAnode current pick-up rate, of which the location is closely related to bath flow. A ‘customized technology for anode set modifierAnode set modifier’ is proposed for anode changesAnode change in different regions. Both numerical and industrial works have proven that this technology played a positive role in improving the heat and electric behavior of ‘sensitive anodes‘Sensitive anodes’’.

Hirakud 85 kA, end-to-end potline was converted to prebake with GAMI technology during 2006–2009. Later, it was observed that, in the existing pot control systemControl system, the application software and control modules are encrypted and hence difficult to modify in line with process requirements. Therefore, control logicControl logic and PLC-based system were developed in-house, in correspondence to the Hirakud pot designDesign and process. During the implementation of the new control systemControl system, the primary challengesChallenges were the acceptability on shop floor and high pot instability due to sludgeSludge forming tendency. Also, preventive and corrective measures are delayed due to high manually intensive operationsOperations. To mitigate the above challengesChallenges, the following actions were taken. (a) Technical training was provided to the shop floor personals. (b) Developed control logicControl logic was modified based on pot conditions. (c) SCADA features, additional reporting, and auto mailing were developed. This article would provide detailed insight into the development and deployment measures.

BauxiteBauxite is the main ore for metallic aluminumAluminum production, consisting of aluminumAluminum and ironIron oxides and kaoliniteKaolinite, a clay mineral commonly found in Amazonian bauxitesBauxite, as the main carrier of reactive silica. In the process, due to the small particle size, kaoliniteKaolinite is usually removed by attrition and washing of coarse material followed by desliming using hydrocyclones. In the Bayer process, kaoliniteKaolinite reacts with sodium hydroxide, increasing reagent consumption in the process. The beneficiation process at Mineração Paragominas is based on the separationSeparation of coarser fractions with higher gibbsiteGibbsite content from the clay minerals, where kaoliniteKaolinite is more concentrated. The separationSeparation takes place in hydrocyclones, equipment that inherently presents a by-pass of fine particles for the underflow, consequently, contaminating the concentrate with kaoliniteKaolinite, and increasing the operating cost in the Bayer process. Additional desliming stages were evaluated for a potential increase in kaoliniteKaolinite removal. Industrial surveying campaigns were carried out and mass balancesMass balance obtained after laboratory characterizationCharacterization and statistical analysis of operational databases. Nageswararao model for hydrocyclones was calibrated and used in tertiary stage simulationSimulation. A black-box model was developed for predicting the benefits of bauxiteBauxite chemical composition. Five routes for bauxiteBauxite silica reductionSilica reduction were analyzed considering the inclusionInclusions of tertiary stages of desliming in cyclones. Process simulationsProcess simulation pointed to a potential solution for the reductionReduction of reactive silica in Paragominas’ bauxiteBauxite, setting tertiary cyclone in fine classification circuit (26″ cyclones) as the most attractive solution, with a potential silica reductionSilica reduction of 4.9%, with 0.4% loss in metallurgical recoveryRecovery of aluminaAlumina.

Due to the fast depletion of bauxiteBauxite resources, beneficiation is a crucial step, mainly to reduceReduce silica and ironIron content. CrushingCrushing technology, grinding, and sieving the bauxiteBauxite in various size fractions are essential for determining suitable feed size during aluminaAlumina production. East Coast bauxiteBauxite was grounded and crushed into different granulometryGranulometry ranging from +2.8 to −0.045 mm. Al2O3 enriched in the coarser fractions, while SiO2, Fe2O3, and TiO2 content increased in finer fractions. There is a decrease in digestion efficiencyDigestion efficiency from coarser to finer size, increasing the specific bauxite and caustic soda consumptionSpecific bauxite and caustic soda consumption. Consequently, up-gradation can be accomplished by discarding a few finer sizes. With an improvementImprovement in bauxiteBauxite quality, for a 1-million-tonnes aluminaAlumina/annum plant capacity, caustic soda consumption can be reduced by approximately 2160 tonnes of NaOH with a savings of 18,000 tonnes of process bauxiteBauxite.

With the increase of requirements for environmental protection, the sintering process with high carbon dioxide emissionEmissions was gradually reduced in the application. However, for low-grade bauxiteLow-grade bauxite, it was difficult to be directly economically utilized by the Bayer process, and a pre-desilicationPre-desilication process was often required. This paper researched the influence of different thermal activationThermal activation temperatures on the pre-desilicationPre-desilication process of low-grade bauxiteLow-grade bauxite. The results showed that the phase transformationPhase transformation of low-grade bauxiteLow-grade bauxite was not much different at different thermal activationThermal activation temperatures, but the pre-desilicationPre-desilication behavior was different. Compared with 650 and 700 °C, the pre-desilicationPre-desilication results of low-grade bauxiteLow-grade bauxite after thermal activationThermal activation at 600 °C had a significant improvementImprovement. Only after 30 min of leaching, the ratio of aluminaAlumina to silica of low-grade bauxiteBauxite can be increased from 2.39 to 6.78. This study may have a certain significance for selecting a suitable thermal activationThermal activation temperature to promote the high-efficiencyEfficiency pre-desilicationPre-desilication of low-grade bauxiteBauxite.

BauxiteBauxite is a rock constituted of minerals and impurities, which are mainly kaoliniteKaolinite, gibbsiteGibbsite, hematite, and anatase. GibbsiteGibbsite is one of the useful minerals for aluminumAluminum production. In mining industries, the quantification of useful minerals and damaging impurities is necessary, with gibbsiteGibbsite reported in levels of available aluminaAlumina and kaoliniteKaolinite, one of the main impurities, as reactive silica. The accuracy of these results influences the measurementsMeasurement of KPI’s (Key Performance Indicators) necessary to determine productivity, helping in decision-making, so the application of a robust methodology to guarantee the quality of determinations, such as R&R (repeatabilityRepeatability and reproducibilityReproducibility), is necessary. R&R analysis of these measurementsMeasurement was performed at Hydro AlunorteHydro Alunorte (Barcarena/PA/Brazil) using 3 different bauxitesBauxite and statistical treatment by ANOVA. Precision/Tolerance values of 6.5 and 10% were reached for the analysis of available aluminaAlumina and reactive silica, respectively. Possibilities for improvementImprovement were implemented, with a significant reductionReduction in reproducibilityReproducibility deviations. With the improvementsImprovement and the data found, it was possible to guarantee the reliability and quality of the results involved.

The Bayer process holds an exclusive status as almost all the world’s metallurgical grade aluminaAlumina is produced by this method. The Pedersen process is an alternative process for the production of aluminaAlumina where bauxiteBauxite ores, or other aluminous materials, are smelted with lime to produce pig ironIron and a slag of mainly calcium aluminate composition. The latter is subsequently leached in Na2CO3 solutions to extract aluminaAlumina hydrate which is calcined to aluminaAlumina. The Pedersen process can handle a wide range of bauxiteBauxite qualities and even bauxite residueBauxite residue from the Bayer process as raw material. Moreover, by-products from the Pedersen process can be used in other industries, thereby eliminating the need for land deposits. An EU-financed project, called EnsureAl, has investigated the possibility of the commercialization of an improved version of the Pedersen process. This paper will summarize the main findings of this project concerning the quality of the produced aluminaAlumina and the by-products. It will also assess a comparison with the Bayer process concerning the estimated costs of the process.

The Hydro AlunorteHydro Alunorte refinery receives bauxite slurryBauxite slurry used in the aluminaAlumina production from Mineração Paragominas, both sites located in Pará—Brazil. This bauxite slurryBauxite slurry, which is dewatered in hyperbaric filters located in Alunorte, has been affecting the lifetime of the pipeline through erosion and corrosionCorrosion processes since the beginning of its transportation in 2008. To increase the lifetime of the pipeline and preserve the dewateringDewatering plant production capacity, this work evaluated the influence of filter rotation, basin level, and feed slurry density on filter productivity by applying a factorial designDesign. The experiment, which was carried out on the industrial filters, complemented the outcome of a previous investigation executed on a laboratory scale using slurry density, top size, and pH as control factors to assess the solids throughput through Box Behnken DesignDesign statistical technique. Results indicated that a top size reductionReduction and pH elevation by the addition of milk of lime decreases the productivity by 13.3%. However, an increase in density, filter rotation, and basin level proved to offset and surpass this predicted loss, making viable the pipeline lifetime increase project and preventing aluminaAlumina production losses in Alunorte.

The Hydro AlunorteHydro Alunorte refinery, located in Pará—Brazil, uses heavy oil, mineral coal and electrical energy boilers in its energy matrix to meet the steam demand of the Bayer process. Aligned with Hydro’s environmental strategyStrategy to reduceReduce greenhouse gas (GHG) emissionsEmissions, Hydro AlunorteHydro Alunorte started operating the first electric boiler with immersed electrode technology as one of the initiatives to increase the share of electricity in the steam generation energy matrix. The new immersed electrode boilerElectrode boiler has higher operational reliability with an availability of approximately 99.5% and with load control by adjusting the level of the electrode chamber, thus loads variation can be done in minutes to control the consumption demand of the refinery. Therefore, it is expected to reduceReduce fuel oil consumption consequently reducing CO2 emissionsEmissions by approximately 150,000 tons per year.

The Hydro AlunorteHydro Alunorte refinery has a complex steam system composed by boilers and power generation turbines that use three types of fuel (heavy oil, coal, and electrical energy) to produce steam for the Bayer process. Due to the complex nature of the refinery and the variable price of fuels, two programs integrated directly with the plant Distributed Control SystemControl system (DCS), aiming to improve energy efficiencyEfficiency and steam system stability, reduceReduce greenhouse gas (GHG) emissionEmissions and avoid cascaded plant shutdowns. Advanced Process ControlProcess control (APC) controls boilers load, steam headers pressure and minimizes relief valves opening. Real Time OptimizationReal-time (RTO) is above APC and is responsible for giving the best configuration to the steam matrix, based on fuel price. This paper will describe how both programs can help steam grid to be stable and financially optimized for the refinery.

Bayer liquorBayer liquor (or named sodium aluminate solution), is a kind of mixed solution from Bayer process, whose boiling pointBoiling point will change while heating according to the thermodynamics properties of multiple components. Bayer liquorBayer liquor obtained from the reaction between bauxiteBauxite and alkaline solution, whose components vary with the bauxiteBauxite characteristics and Bayer process condition. Based on the analysis of Bayer process, the boiling pointBoiling point of Bayer liquorBayer liquor has a significant effect on the energy consumption and evaporation efficiencyEfficiency during evaporation process one of the most important sections in the Bayer process, in which realizing alkaline solution concentration, water balance and carbonate removal. However, it is hard to calculate the boiling pointBoiling point using the theory formula directly. To overcome above problemsProblems, the effects of impurities on the boiling pointBoiling point of Bayer liquorBayer liquor were investigated using simulation methodSimulation method, which can bring us useful guidance to setup criterion for the impurities management during Bayer process.

β″-Al2O3Β″-Al2O3 was prepared at 1280 ℃ using α-Al2O3, γ-Al2O3, and boehmiteBoehmite as aluminaAlumina precursors and NaHCO3 as sodium oxide source. The effect of different aluminaAlumina precursors and amounts of NaHCO3 on β″-Al2O3 formation behavior were studied. The phase composition and microstructureMicrostructure of the as-prepared β″-Al2O3Β″-Al2O3 were analyzed, respectively, by X-ray diffraction and scanning electron microscopyScanning electron microscopy (SEM). β″-Al2O3 co-existing with NaAlO2 and α-Al2O3 was obtained when using α-Al2O3 and γ-Al2O3, whereas phase-pure β″-Al2O3Β″-Al2O3 was prepared by calcining the mixture of boehmiteBoehmite and 22 wt% of NaHCO3. The phase-pure β″-Al2O3 particlesAl2O3 particles did not agglomerate and showed a sheet-like morphology with a thickness of about 1 μm.

This paper briefly introduces a reference materialReference material for the determination of α-phase in aluminaAlumina powders (aluminumAluminium oxide) with X-ray diffractionX-ray diffraction methods, and focuses on the measurementMeasurement and characterizationCharacterization of the crystal cell parametersCell parameters. The α-phase aluminaAlumina powder reference materialReference material was made of boehmiteBoehmite as a precursor through high-temperature calcination, screening and homogenizationHomogenization, and it had no preferred orientation in the detection, and its diffraction peak intensity was high and stable, which was a challengeChallenges with other precursor materials. According to the requirements of GB/T 15,000 “Directives for the Work of Reference MaterialsReference material”, the statistical method was adopted by 8 testing institutions to complete the determination of the crystal cell parametersCell parameters. After evaluation and statistical analysis, the crystal cell parametersCell parameters of the aluminaAlumina reference materialReference material were determined to be: a = 0.47592 ± 0.00002 nm, c = 1.29921 ± 0.00008 nm, which met the Joint Committee on Powder Diffraction Standards (JCPDS) standard card 00–043-1484.

A robust management systemManagement system guarantees the stability and predictability of a company’s processes. The focus is on continuous improvementContinuous improvement, supported by people, in structured methodologies, through a recognitionRecognition program to leverage initiatives to contribute to sustainable business. Coordinating different facets, integrating areas, evolving its structure, and using Lean principles, focusing on people makes the challengeChallenges even more complex. This project presents the technical evolution of a recognitionRecognition and improvementImprovement program in the bauxiteBauxite and aluminaAlumina business in Pará, Brazil. In 2022, it had more than 600 improvementImprovement projects that generated an engagementEngagement of more than 670 people with proven gains in dimensions such as health, safetySafety, environmentEnvironment, quality of life in the work environmentEnvironment, innovation, and current income in the millions level (US$). It indicates a growing potential for the involvement of teams in the development of improvementsImprovement. The consequence is sustainabilitySustainability in achieving the global company’s goals.

A low-cost approach to bauxite residueBauxite residue (BR) utilization has not been achieved due to the complicated mineralogy. In this study, BR has been treated by dilute acid to reduceReduce the alkalinity of residue by dissolving sodaliteSodalite phase. The acid washed BR samples are of high ironIron grade (>80% Fe2O3) with low sodium content (<0.3% Na2O) which can be potentially used as ironmaking feed. The washed acid solution was treated by caustic NaOH to synthesise the zeolite-like adsorption materials. The materials have been used for adsorption of copperCopper and lithium metal salts. The Cu adsorption performance of the synthesised product shows the exhibits fast loading kinetics as within 15 min over 99% of adsorption efficiencyEfficiency is observed, compared with commercial grade zeolite LTAZeolite LTA.

Bauxite residueBauxite residue (BR) is a by-product of the Bayer process for aluminaAlumina production. The physical and chemical characteristics of BR from gibbsitic bauxiteBauxite such as the fine particle size distribution and mineralogical phases (hematite, sodaliteSodalite, goethite, anatase, gibbsiteGibbsite and quartz) prevent its wide use and limit the recoveryRecovery of elements by conventional physical operationsOperations. As an example, the magnetic recoveryRecovery of hematite from gibbsitic RB is unfeasible. An alternative to enable a magnetic concentration operationOperations would be to obtain higher magnetic susceptibility phases, whose magnetic properties could overcome the processingProcessing limitation determined by the fine size of the RB particles. In this work, a Brazilian BR from gibbsitic bauxiteBauxite processingProcessing with an ironIron and titaniumTitanium concentration of 47.03% Fe2O3 and 5.45% TiO2 was re-digested in presence of ironIron(II) sulphate 7-hydrate (FeSO4•7H2O), at high temperature (230ºC) and high caustic concentration (370 g/l Na2CO3). MagnetiteMagnetite, ulvite (titaniumTitanium-magnetiteMagnetite) and cancrinite minerals were obtained. The results demonstrated that this route may be promising for magnetic ironIron recoveryRecovery, especially if side reactions were minimized. For future studies, one should evaluate the threshold for the conversion when the severity of conditions was diminished, as well as, the assessment of magnetic properties and the evaluation of potential recoveryRecovery of the magnetic product.

Bayer digestionBayer digestion performance of gibbsiteGibbsite-boehmiteBoehmite bauxiteBauxite is studied in this paper. The chemical and mineral compositions of a gibbsiteGibbsite-boehmiteBoehmite bauxiteBauxite from Australia are analyzed and tested by XRF, XRD, and SEMScanning electron microscopy (SEM). Test results show that the bauxiteBauxite contains ≥ 50% of aluminaAlumina (gibbsiteGibbsite and boehmiteBoehmite) and 9% of silica (kaoliniteKaolinite and quartz). Its digestion efficiencyDigestion efficiency is studied in detail with various digestion conditions such as temperatures, holding timesHolding time and additivesAdditive. A medium temperatureMedium temperature digestion technology has been developed based on the study results and industrial tests in Chinese refineries: boehmiteBoehmite in the bauxiteBauxite will be totally digested in just a few minutes with bits of lime addition for a high aluminaAlumina recoveryRecovery efficiencyEfficiency and most of the unreactive silica minerals in the bauxiteBauxite are at a stable state with caustic consumptionCaustic consumption reduced by over 10%, aluminaAlumina recoveryRecovery efficiencyEfficiency increased by 2–3% compared with traditional digestion technologies. There is a great application prospect with this medium temperatureMedium temperature digestion technology for the Australian bauxiteBauxite.

Among the challengesChallenges faced by the mineral industry, issues related to reductionReduction on water consumption, tailingsTailings disposal, and environmental management are highlighted. It is fundamental to study dewateringDewatering methods to improve the sustainabilitySustainability of the mineral activity. Different methods can be seen worldwide, and decanter centrifugesDecanter centrifuge are already an option for dewateringDewatering tailingsTailings on different operationsOperations. Regarding bauxiteBauxite mines, it is estimated that tons of tailings are disposed every year, mainly in settling ponds or tailings dams. Since typical bauxiteBauxite concentration consists basically in washing the ore and removing fine particles from the product, the bauxiteBauxite tailings consist of fine kaoliniteKaolinite, what makes the dewateringDewatering operationOperations even more challenging. In this scenario, the purpose of the current work is to analyze the bauxiteBauxite tailings dewateringDewatering by decanter centrifugeDecanter centrifuge, with the tailings from bauxiteBauxite processingProcessing fed by ore from Minas Gerais, Brazil.

TitaniumTitanium diboride (TiB2) and titaniumTitanium carbide (TiC) are both widely used as grain refinersGrain refiner in the production of DC-cast aluminumAluminum ingot for rolled products. This study evaluated industrially produced DC-cast aluminumAluminum ingot of alloy AA5182 with TiB2 and TiC and the grain refinersGrain refiner’ impact on ingot surface condition, as-cast microstructureMicrostructure, rolling performanceRolling performance, grain size distribution, as well as final product mechanical propertiesMechanical properties. Through optical microscopy and SEMScanning electron microscopy (SEM)-EDS metallographic examination of the sheet post-hot rollingHot rolling, the study found that the use of TiC grain refinerGrain refiner resulted in fewer surface stress risers and improved surface quality, rollability, and edge crackingEdge cracking performance of AA5182. It also improved grain size uniformity and created less grain refinerGrain refiner agglomerationAgglomeration versus the same alloy cast with TiB2 grain refinerGrain refiner.

The use of 6xxx series6xxx series aluminumAluminum extrusionsExtrusion inAluminum extrusion alloys automotiveAutomotive applications is increasing due to the requirement to reduceReduce vehicle weight. Extruded profiles can be subjected to severe and complex plastic strain pathsPath during fabrication or during crash loading. During the extrusionExtrusion process, deformation gradients develop due to (i) friction between the tooling and the extrudate, (ii) redundant work, and (iii) splitting of the extrusionExtrusion and weldingWelding in porthole diesPorthole dies when fabricating hollow profiles. The current study examined these effects in materials with high dispersoidDispersoids densities at relatively low extrusionExtrusion temperatures (~400 °C) where recrystallizationRecrystallization was deliberately suppressed. Local texturesTextures were characterized using electron backscatter diffraction (EBSDElectron backscatter diffraction (EBSD)) and the local stress–strain response was predicted using the visco-plastic self-consistent (VPSC) polycrystal plasticity model. The results were used to rationalize (i) the inhomogeneity of through thickness deformation during tensile testing and (ii) the localization of plastic deformation at the weld seam.

Mechanical propertiesMechanical properties, microstructuresMicrostructure and texturesTextures of cold rollingRolling sheets from a low-cost continuous castingContinuous casting (CC) Al-1.5Cu alloy were characterized and investigated thoroughly using tensile testing machine, Optical & Scanning Electron microscopes (SEMScanning electron microscopy (SEM)), and X-ray diffractometer (XRD). Compared with AA5xxx and AA3xxx aluminum alloysAluminum alloys, ascribing to the precipitationPrecipitation and solid solution of Al-Cu phase, material characteristics of the Al-Cu alloyAl-Cu alloys after cold rollingRolling at different gauges are significantly different with some interesting findings. The findings from the cold rollingRolling hardening would potentially affect the subsequent processingProcessing, such as solid solution heat treatmentHeat treatment, quenching, forming, and agingAging, for application (replace AA5xxx-O sheet) in auto sheets.

An industrial trial to produce 57545754 alloy automotiveAutomotive application sheets through the twin roll castingTwin roll casting (TRC) route was carried out in ELVAL’s rollingRolling plant. The paper describes several challengesChallenges faced to produce final product within the automotiveAutomotive customer specifications using the twin roll castingTwin roll casting (TRC) process. Microstructural control, as-cast surface quality (level lines), and final mechanical propertiesMechanical properties are the major challengesChallenges in 57545754 sheet production via twin roll castingTwin roll casting (TRC). Microstructural control refers mainly to the final soft temper grain size and the amount of the central line segregationSegregation phase. CastingCasting two different 57545754 alloy versions with respect to Mn content (high and low Mn alloy) and rollingRolling the coils to final gauge using the same thermomechanical process shows clearly the significant influence of alloy Mn content in the final grain size and the final mechanical propertiesMechanical properties.

The present work deals with the fabrication of rolled aluminumAluminum sheets based on 5xxx5xxx alloys, striving for a superior appearance and formabilityFormability. Due to the material’s exceptional surface properties, processability and corrosionCorrosion resistance, the developed material may be employed to manufacture sophisticated designDesign elements dedicated to the automotiveAutomotive industry. Beyond optical investigations conducted on brightened and anodized material, phase studies are carried out, suggesting thermal processingProcessing close to the solidus temperature prior to cold rollingRolling. This is backed up by thermodynamic simulationsThermodynamic simulation, dealing with the impact of precipitates on the material’s appearance. Moreover, the grain structureGrain structure as well as mechanical propertiesMechanical properties in temper H2X are tackled, addressing the demand for decorative elements with a sufficient formabilityFormability and enhanced corrosionCorrosion resistance.

The automotiveAutomotive industry has started using lightweight materials like aluminumAluminum with the aim of increasing fuel efficiencyEfficiency by supporting carbon neutral production. Structural parts of an automobile like bumper and chassis requires not only tensile strengthTensile strength but also crashworthinessCrashworthiness. One of the main requirements of an aluminum alloyAluminum alloys is to increase crashworthinessCrashworthiness by over agingAging of the alloys. In this study, 6005 aluminum alloyAluminum alloys production has been followed with automotiveAutomotive parts production route of billet production by direct chill castingCasting, homogenizationHomogenization, extrusionExtrusion and heat treatmentHeat treatment. Different natural and artificial agingAging conditions have been applied to 6005 alloy6005 Alloy. Strengths, crashworthinessCrashworthiness, elongationsElongation and fractureFracture characteristics have been evaluated according to the results of characterizationCharacterization studies including tensile tests and SEMScanning electron microscopy (SEM) Analysis.

The starting point of the research project was the control of the homogenizationHomogenization process of EN AW 3003 aluminium alloyEN AW 3003 aluminium alloy. For this purpose, thermodynamic simulationsThermodynamic simulation of the studied alloy were carried out using the Thermo-Calc program to determine the temperature stability of the different phases and the equilibrium concentrations of these phases vs. temperature. HomogenizationHomogenization annealingAnnealing was simulated using differential scanning calorimetryDifferential scanning calorimetry (DSC) and electrical resistance measurementMeasurement to determine the suitability of such measurementMeasurement for optimizing the homogenizationHomogenization process. The efficiencyEfficiency of the homogenizationHomogenization time was investigated using a standard homogenizationHomogenization process of the as-cast samples from the slab in the furnace, followed by a detailed microstructureMicrostructure analysis. Very good agreement was obtained between the simulationSimulation of homogenizationHomogenization with DSC analysis and the electrical resistivityElectrical resistivity curve, confirming the suitability of the electrical resistivityElectrical resistivity measurementMeasurement method for monitoring the homogenizationHomogenization process of aluminium alloysAluminium alloys.

Edge crackingEdge cracking during hot rollingHot rolling of aluminumAluminum 6000-series ingots presents a challengeChallenges to rollingRolling mills, resulting in costly rework, scrap loss, and downtime. The sodium element is known to be a critical contributing factor to edge crackingEdge cracking, while silicon, magnesium, and titaniumTitanium content, within typical limits, does have a noticeable effect. The inverse segregationSegregation zone and meniscusMeniscus bands are found to serve as potential sites for edge crack initiation and propagation and must be minimized with appropriate castingCasting practices. This study was performed to identify key processes and metallurgical factors of using DC-cast octagonal AA6016AA6016 ingots to reduceReduce edge crackingEdge cracking during hot deformation. A microstructural investigation was conducted with an optical microscope and SEMScanning electron microscopy (SEM)-EDS to understand the impact of using eight-sided ingots. An industrial trial was realized to evaluate the rolling performanceRolling performance and metallurgical characteristics of octagonal ingots compared to the standard rectangular form.

The recyclingRecycling of wrought aluminum alloysWrought Aluminum Alloys from end-of-life products is only carried out to a limited extent. The obstacles are the lack of: (i) an appropriate chemical composition of the recycled meltMelt and (ii) sufficient reliable sources. Both can be eliminated through the consistent traceability of alloys in end-of-life products at all stages of circular aluminumAluminum management. This paper describes the process of ensuring the universal traceability of aluminum alloysAluminum alloys by type of alloy, by manufacturer, and by location in the end-of-life product. Tracking begins with the disassembly of end-of-life products into their components or components made from wrought aluminum alloysWrought Aluminum Alloys. We have built an innovative concept of ensuring the traceability of Al alloysAl alloy using barcodes, which can be improved with more advanced versions. The solution enables the consistent separationSeparation and extraction of the highest-quality scrap from end-of-life products, comparable to the quality of the return material. This is, as an option, usually returned to the alloy manufacturer, and can be melted directly into wrought alloys. The solution enables significant decarbonizationDecarbonization of production and an increase in the added value of the products.

Reducing the inclusionInclusions levels in AluminumAluminum is quite challenging considering the metal cleanlinessMetal cleanliness methods starting from TAC (Treatment AluminumAluminum in Crucibles) until the AluminumAluminum been charge into the furnace which then contains a degasser unit to remove the hydrogenHydrogen from going into the metals a longLong with A 94 (deep bed filter). Our study was conducted to reduceReduce inclusionInclusions level in AluminumAluminum which supply slab. The inclusionInclusions depends upon the percentage of (CRU (Can RecyclingRecycling Unit), reductionReduction, remelt). Our aim was to study the inclusionInclusions level with different product mix and minimize the inclusionInclusions levels with specified metal input mix (CRU, remelt and reductionReduction metal). This study will be done on MRC slab product. (Ma’aden RollingRolling Mill Company) with slab ingot of 3xxx, and 5xxx5xxx, and it has to go through metal cleanlinessMetal cleanliness test such as PodfaPoDFA, Limca, and Alscan to verify the metal cleanlinessMetal cleanliness. The study will provide the inclusionInclusions levels with different product mix and will suggest the best metal input mix to minimize the inclusionInclusions levels in Slab product.

The increased use of aluminiumAluminium scrap in the production of cast wheels is considered as a condition to satisfy the global trend for carbon footprintCarbon footprint reductionReduction. AlSi11 alloy is widely used in the production of wheels by LPDCLPDC-process. Typically, the ironIron content in this alloy does not exceed 0.19wt.%. The increase of the percentage of aluminumAluminum scrap leads to higher ironIron content in the meltMelt. In the Al-Si alloysAl-Si alloys, ironIron tends to form the needle-like β-phase Al5FeSi, presence of which in the structure can significantly reduceReduce the ductilityDuctility of the alloy. The addition of manganeseManganese as an alloying element is used in practice in order to transform the needle-like β-phase Al5FeSi into a less harmful “Chinese script”-like α-phase Al15(Fe, Mn)3Si2. The authors investigated the effect of various Fe/Mn content on the structure and mechanical propertiesMechanical properties of the AlSi11 LPDCLPDC-wheels to ensure the amount of Fe tolerated in the alloy.

Shear Assisted ProcessingProcessing and ExtrusionExtrusion (ShAPE) was used to fabricate aluminum alloyAluminum alloys 6063 tubing directly from secondary scrap. Trimmings from an automotiveAutomotive manufacturing facility were cast into billets and spiked with ironIron (0.3 wt.% Fe) to explore the tolerance of ShAPE to Fe contamination. Billets were extruded in the unhomogenized condition to form tubing with an outer diameter of 12 mm and wall thickness of 2 mm. Tensile properties reached 0.2% YS = 206 MPa, UTS = 238 MPa, and U.E. = 16.3% in the T6 temper. Properties exceed the ASTM minimum standard and are on par with ASM typical values for conventional extrusionExtrusion of primary aluminumAluminum billets in the fully homogenized condition. Property equivalence between conventional extrusionExtrusion of homogenized primary aluminumAluminum billets with nominal Fe, and ShAPE extrusionExtrusion of unhomogenized secondary aluminumAluminum billets with high Fe, are attributed to the highly refined microstructureMicrostructure achieved with ShAPE. Microstructural characterizationMicrostructural characterization shows an extensive refinement of grain size along with dispersion, refinement and homogenizationHomogenization of FeAlSi and MgSiO intermetallic phases. This study suggests that ShAPE extrusionExtrusion may offer a lower carbon manufacturing pathway through direct recyclingRecycling of secondary aluminumAluminum scrap with high Fe content and elimination of the billet homogenizationHomogenization step.

Shear Assisted ProcessingProcessing and ExtrusionExtrusion (ShAPE), a severe plastic deformation technique that is fast and scalable, was used to produce thin-wall tubing from alloy 6082 (Al-0.8 Mg-0.9Si-0.7Mn) with in-situ solutionization during processingProcessing quickly followed by quenching. Quench medium and input material heat treatmentHeat treatment were varied and natural agingAging behavior (T1 heat treatmentHeat treatment) was evaluated using tensile testing. Post-ShAPE, the as-cast material was found to have high initial strength but weak natural aging, while the homogenized material was found to have lower initial strength and greater natural aging. Compared to air quenching, water quenching gave greater strength both early in and after natural agingAging. These observations along with microscopy suggest that: 1. air quenching was too slow; 2. as-cast material was not fully solutionized but plastic deformation broke up the coarse intermetallic particles, which provided strengtheningStrengthening; and 3. homogenized material was solutionized well, which led to good natural agingAging behavior.

Aluminium alloysAluminium alloys reinforced with ceramic particles have been extensively investigated for automotiveAutomotive applications. Presently, growing attention has been drawn to their application within electric vehiclesElectric vehicle due to their high strength and lightweight. Among various reinforcements, titaniumTitanium carbide (TiC) is of particular interest due to its superior hardness, high wearWear resistance, excellent elastic modulus, and relatively low coefficients of thermal expansion. This study aims to explore the effect of nano-/submicron-sized (<2 µm) TiC particlesTiC particles on the mechanical propertiesMechanical properties of a commercial aluminium alloyAluminium alloys by incorporating Al-45 wt.% TiC master-alloy powders and Al-6 wt.% TiC master ingots. Stir castingCasting with the aid of ultrasoundUltrasound processingProcessing was applied to facilitate the mixing and dispersion of the TiC particlesTiC particles. Composites with additions of 0.5, 1, 2, and 5 wt.% TiC were prepared by gravity castingCasting using a permanent steel mould. The effect of the TiC particlesTiC particles on the microstructureMicrostructure, with respect to castingCasting defects, particle distributions, and particle/matrix bonding has been investigated.

EN AW 6082EN AW 6082 alloys are used in many different areas from construction to automotiveAutomotive industry. EN AW 6082EN AW 6082 alloys have one of the highest mechanical propertiesMechanical properties in the 6XXX6xxx group. Studies on the quench rate of this alloy have significant importance to observe its behavior in different conditions industrially. The present work was conducted to investigate the manganeseManganese modification effect on microstructureMicrostructure and mechanical propertiesMechanical properties, depending on the quench rate of this alloy. Low and high Mn contained samples homogenized industrial practical and end quench test methodEnd-quench test method was applied. Then, samples were aged for different durations between industrially chosen temperature levels. Depending on quenching sensitivity, mechanical propertiesMechanical properties and microstructureMicrostructure differences were determined on the minimum and maximum Mn contained aluminum alloysAluminum alloys.

Extensive laboratory tests have been performed on 20 AluminumAluminum Conductor Steel Reinforced (ACSR) conductors that were sampled from Hydro-Québec overhead transmission linesOverhead transmission lines. A series of tensile tests along with metallographic analyses were carried out to reveal the mechanical propertiesMechanical properties and the remaining thickness of the coated zinc on steel strands. The age, geometry, current, and the type of environmentEnvironment corresponding to each ACSR conductorACSR conductor, were considered to quantify the ageing and degradationDegradation behavior of conductors. It is shown that as the conductor ages, the zinc loss on steel strands triggers the decrease in mechanical propertiesMechanical properties. An aggressive environmentEnvironment induces a higher decrease in the remaining zinc thickness. However, a higher number of aluminumAluminum wire layers and diameters can retard this degradationDegradation. It was revealed that a low current conducted through the wires might lead to higher degradationDegradation.

A eutecticEutectic Al alloyAl alloy containing 1.8 wt.% Fe (Al-1.8%Fe) for electric vehiclesElectric vehicle was prepared by permanent steel mold castingCasting (PSMC) along with commercial-purityPurity (CP) Al (99.7%). The mechanical propertiesMechanical properties including ultimate tensile strengthTensile strength (UTS), yield strength (YS), and elongationElongation (ef) were evaluated by tensile testing. The electrical conductivityElectrical conductivity was measured by the phase-sensitive eddy current method. The addition of 1.8 wt.% Fe increased both the UTS and YS of the cast CP Al significantly to 86.5 and 28.3 MPa from 34.5 to 12.3 MPa. However, the ef and electrical conductivityElectrical conductivity of the cast alloyCast alloys decreased to 19.8% and 48.4%IACS from 33.8% and 58.5%IACS. The large area fraction of the eutecticEutectic Al–Fe phases in the PSMC Al-1.8%Fe alloy should be responsible for the difference in mechanical and electrical properties between the PSMC Al-1.8%Fe alloy and the PSMC CP Al.

Friction stir weldingFriction stir welding has gained importance as an effective way to join dissimilar materials due to its solid-state nature. However, the effects of plastic deformation with increased tool rotation, traverse speed, and plunging force on the mechanical propertiesMechanical properties of the weld material are poorly understood. In the current study, electron backscatter diffractionElectron backscatter diffraction (EBSD), microhardnessMicrohardness, and inductively coupled plasma emissionEmissions analyses were used to characterize two distinct groups of welds conducted in a lap weld configuration joining 6061 and A365 aluminum alloysAluminum alloys. The grain structureGrain structure reveals clear distinctions between the expected dynamically recrystallized zone, the thermomechanical affected zone, and the heat-affected zone with varying microhardnessMicrohardness between weld groups. The first weld group was conducted at high rotational speed, traverse speed, and plunge force compared to the second weld group. Furthermore, this study finds that the distribution and generation of precipitates is not the main factor leading to increased surface hardnessSurface hardness between the weld groups. Instead, the additional textureTextures resulting from increased plastic deformation as the operationOperations's rotational speed, traverse speed, and plunging force increase is found to cause the mechanical propertyMechanical properties variation between the weld operationsOperations.

The aluminum alloyAluminum alloys 7010 is widely used in the aerospace industry due to its comparatively lightweight and high strength. Shot peening is an important surface modification procedure for structural materials meant for improving the fatigue life. The surface properties can be further enhanced by changing the temperature of the surface during the process of peening. In this study, shot peening at room and high temperaturesHigh temperature shot peening ranging from 100 to 300 °C was performed at an Almen intensityAlmen intensity of 0.15 mmA, on cylindrical specimens of AA7010-T74527010-T7452 aluminum alloy. The influence of the process on surface roughnessSurface roughness, residual stresses, hardness, and microstructureMicrostructure was investigated. The results showed that the surface roughnessSurface roughness increased with the temperature of shot peening and an optimized peening temperature of 250 °C was identified from the variation of hardness profiles.

In this work, we present the use of an ultrafast laserLaser system for the high aspect ratio micro-drilling of aluminum alloyAluminum alloys thin foils. Hole sizes in between 20 and 40 μm were fabricated in arrays with sub-micron level precision in terms of diameter and hole location. The Design of ExperimentDesign of experiment approach was employed to analyze the influences of the laserLaser process parametersProcess parameters like laserLaser power, frequency, and exposure time on the resulting quality of the produced micro-holes. The outputs measured were hole size, location and the variability in these measures. The metallurgical and geometrical features were examined using a scanning electron microscope and optical microscope. ProcessingProcessing throughput is also important in industrial laserLaser processes. The parametric effect on circularityCircularity and taperTaper has been observed to understand the features of the hole. The features of holes help in fabrication in a plethora of industries to produce applications such as fins, filters, microgrid circuits, and biomedical devices.

6xxx series6xxx series aluminum alloysAluminum alloys are increasingly used within the automotiveAutomotive industry due to their lightweight potential. For assembling several joining techniques are common. This paper focuses on adhesive bondingAdhesive bonding, which is widely employed but its mechanism is by far not fully understood. The sheet metal process, including hot and cold rollingRolling, solution heat treatmentHeat treatment, pickling and Ti/Zr conversion treatment, contributes heavily to the final bonding performance. Even minor changes in the rollingRolling process may alter the surface near deformation layer or a variation during pickling can lead to unfavorable oxidic conditions. To evaluate these changes X-ray photoelectron spectroscopy (XPS)X-ray Photoelectron spectroscopy (XPS), which is extremely powerful in gathering elemental, chemical and oxidic information from the topmost surface (<10 nm), was performed. Furthermore, transmissionTransmission transmission Kikuchi diffraction (TKD) in combination with a focused ion beam (FIB) preparation was employed to investigate the surface near grain structureGrain structure near grain structure. Additionally, scanning electron microscopy (SEM)Scanning electron microscopy (SEM) provided valuable knowledge concerning the surface topography.

The main alloying element of 2011 aluminum alloy2011 aluminum alloy is copperCopper and it is disadvantageous from the point of corrosionCorrosion compared to other aluminum alloysAluminum alloys. 2011 alloy also contains bismuth and lead in their chemical composition. These elements have low melting pointMelting point and enhance machinability of the alloy. In this way, 2011 alloys are frequently used in areas where machinability is important. Also, 2011 alloys are preferred in valve manufacture and therefore understanding its corrosionCorrosion behavior is critical. In this study, 2011 aluminumAluminum billets were produced by direct chill (DC) castingCasting and then homogenizationHomogenization was carried out. As the next step, billets were extruded. Different samples were taken from extruded profiles and heat treated to obtain T4, T6, T79, T73 conditions. Samples were then hard anodized. After anodizing, samples were taken to corrosive environmentEnvironment. Optical microscope, Scanning Electron Microscope (SEMScanning electron microscopy (SEM)) and Energy Dispersive Spectrometry (EDS) techniques were used for characterizationCharacterization and corrosionCorrosion behavior of 2011 alloy under different heat treatmentHeat treatment conditions was investigated. It was found that T6 condition, which is the most preferred heat treatmentHeat treatment condition for 2011 alloys, has the maximum corrosionCorrosion depth and other experimental results obtained agree well with expected properties.

The microstructureMicrostructure of aluminiumAluminium (Al) and its alloys is a well-investigated key parameter utilized to adjust their mechanical, chemical, and physical properties. The microstructureMicrostructure of Al can be altered by several processes, such as controlled solidificationSolidification rate, grain refinerGrain refiner additions, and external force fields. The present study has chosen to focus on conventional procedures for grain refinementGrain refinement and compare the results to new low-energy concepts. In view of this, three different commercial grain refinersGrain refiner (2 different AlTi3B1, AlTi5B1) were added to lean 1370 and AlSi7 aluminium alloysAluminium alloys at (i) different solidificationSolidification rates, and (ii) influenced by alternating electromagnetic fields. The results were evaluated based on the effects on grain size and electrical conductivityElectrical conductivity. The initial results revealed an inverse relationship between the conductivityConductivity and the final grain size, which also proved to be independent of the origin of the refined grain structureGrain structure.

This study investigates the use of ultrasoundUltrasound to refine the microstructureMicrostructure of cast aluminum alloysAluminum alloys during solidificationSolidification and thus improve their mechanical propertiesMechanical properties. An A356 aluminum alloyA356 aluminum alloy (Al–Si–Mg) with added Fe (to mimic a recycleRecycle-grade alloy) was cast in a graphite mold with the simultaneous application of ultrasoundUltrasound via an ultrasoundUltrasound probe inserted in the mold. Tensile specimens were extracted from the castingsCasting and heat treated to a T6 temper. Ultrasonication during castingCasting transformed the morphology of primary aluminumAluminum grains from dendritic (~140 microns in size) to globular (~36 microns in size). The ultrasonically refined microstructureMicrostructure had 88% greater ductilityDuctility, on average, and up to 10% greater tensile strengthTensile strength than the dendritic microstructureMicrostructure. This improvementImprovement in strength and ductilityDuctility demonstrates the potential for ultrasonic processingProcessing to improve the performance of cast aluminum alloysAluminum alloys without altering their chemistry or additional post-processingProcessing.

In order to understand the solidificationSolidification behavior and microstructural evolution of the Al–Cu–Si ternary eutectic alloyTernary eutectic alloy system, the evolution on the microstructureMicrostructure of the Al–Cu–Si ternary eutectic alloyTernary eutectic alloy with different pre-heating mold temperatures was investigated. When the mold was preheated at 500 °C, the primary Si and Al2Cu dendrites were mainly observed and (α-Al + Al2Cu) binary eutecticEutectic and needle-shaped Si phase were also developed. When the mold preheatingPreheating temperature was 300 °C, the primary Si and Al2Cu dendrites were observed with colonial regions where the (α-Al + Al2Cu + Si) ternary eutecticEutectic phase was also present. When the mold preheatingPreheating temperature was 150 °C, the bimodal structure which composed of (α-Al + Al2Cu) binary eutecticEutectic phase and (α-Al + Al2Cu + Si) ternary eutecticEutectic phases was observed When the mold preheatingPreheating temperature was changed from 500, 300, and 150 °C, Si phase undergoes the most distinctive microstructural changes. When it passed the critical cooling rate, the (α-Al + Al2Cu + Si) ternary eutecticEutectic was formed. It was concluded that the growth of Si phase was suppressed by the high cooling rate and the growth of Al and Cu containing eutecticEutectic phases, which grow cooperatively, were also suppressed. This resulted in the ternary eutectic alloyTernary eutectic alloy with a finer microstructureMicrostructure.

Arc weldingWelding high-strength aluminum alloysAluminum alloys is a great challengeChallenges due to characteristic defects upon melting and re-solidificationSolidification. However, it is an economical method by which these important engineering alloys can be processed. An emerging metallurgical technique known as nano-treatingNano-treating has seen increasing use in tandem with classical metallurgy, with the latest advances being presented here. Incorporating a small volume fraction of nanoparticles into the weldingWelding process significantly alters the associated structure/processingProcessing/property relationships and enables the joining of difficult-to-weld aluminum alloyAluminum alloys systems. From a structural perspective, nanoparticles suppress the formation of dendrites, refine grains, and attenuate large secondary phases that exist in conventional arc weldingWelding, thus eliminating hot cracking. The microstructural evolution that nanoparticles permit along with traditional strengtheningStrengthening mechanisms elevates the performance of the weld over its traditional barriers. Thus, the nano-treatingNano-treating approach paves the way for new possibilities in arc weldingWelding high-strength aluminum alloysAluminum alloys and other “unweldable” systems.

SolidificationSolidification of aluminium alloysAluminium alloys is a complex process in which inhomogeneities form. AluminiumAluminium and ironIron form the equilibrium phase Al13Fe4 and various metastable intermetallic phases: Al6Fe, AlmFe, and AlxFe. Three alloys were prepared and analysed in the laboratory: AlFe1, AlFe1Si0.1, and AlFe1Si0.5. Thermodynamic calculationsThermodynamic calculation, differential scanning calorimetryDifferential scanning calorimetry, electrical resistivityElectrical resistivity measurementsMeasurement, and optical and scanning electron microscopyScanning electron microscopy (SEM) were used to analyse the alloys. The results show that the addition of silicon to the AlFe1 alloy has a great influence on the distribution, amount, and morphology of the phases formed during the solidificationSolidification process. The addition of 0.1 wt.% Si reducesReduce the amount of metastable Al6Fe phase. The transformation sequence was defined, starting with the dissolutionDissolution of the metastable phaseMetastable phase and the nucleation of the stable phase Al13Fe4. Due to the increased diffusion lengths of the ironIron atoms, the transformation takes place in the eutecticEutectic range after 4 h of homogenizationHomogenization at 600 °C.

Metal matrix compositesMetal matrix composites offer improved mechanical propertiesMechanical properties at reduced weight compared to monolithic alloys. The reinforcing capabilities of the particulate are dependent on their size, distribution, and bonding with the matrix. The intermetallic compound, Al3Ti, has excellent bonding with the surrounding matrix but can grow detrimentally large with extended hold times in the molten state. In addition, passing electrical current at low power levels through the meltMelt has been found to reduceReduce the size of the Al–Ti intermetallic phase. This research focuses on the novel processingProcessing method of passing an electric current through molten aluminum alloyAluminum alloys to refine the reinforcing secondary phase. This technique could have broad impacts on particulate refinement in multiple metal matrix compositeMetal matrix composites systems.

The manufacturing associated with emerging technologies, including electric vehiclesElectric vehicle, is impacting demand for cast aluminium alloysAluminium alloys, including those based on the Al–NiAl-Ni system. These alloys typically have a eutecticEutectic with a fine lamellar spacing in the as-cast condition, display high thermal stabilityThermal stability, high electric conductivityConductivity, resistance to hot tearing, good fluidityFluidity, and strength. These properties combined make this alloy system suitable for a variety of applications. This research investigates the effect of varying the concentration of Ni on the solidificationSolidification mode, microstructureMicrostructure, and fluidityFluidity of Al–NiAl-Ni alloys. Hypoeutectic, eutecticEutectic, and hypereutectic compositions of Al–NiAl-Ni from 0 to 10 wt.% were investigated, and it was found that hypereutectic Al–7.7wt.%Ni alloy had the best fluidityFluidity. As cast microstructuresMicrostructure were compared to investigate microstructure evolutionMicrostructure evolution in the Al–NiAl-Ni system.

To study the effect of Ti–B content on the microstructureMicrostructure and mechanical propertiesMechanical properties of Al-7Si and Al-12.6Si alloys with Al-5Ti-1BAl-5Ti-1B content of 0% and 2%, respectively, were prepared through conventional melting and castingCasting route. The microstructureMicrostructure and mechanical propertiesMechanical properties of as-cast alloysCast alloys were investigated, and a correlation has been establishedEstablished between microstructural features (shape, size, and area of eutecticEutectic Si, SDAS of primary α-Al, inter-spacing between two nearby eutecticEutectic Si particles, and hardness) with strength and ductilityDuctility of as-cast alloysCast alloys. Results show that Ti content changes the morphology of primary α-Al grain from dendrite to rosette type in Al-7Si alloy and coarse dendrite to fine columnar dendrite in Al-12.6Si alloy. EutecticEutectic Si particle’s shape and size also change with the addition of Ti to the meltMelt. The thermally stable phase Al3Ti is associated with Si and forms the Ti7Al5Si14 phase. Lower SDAS values, finer dendrite α-Al grains, reduce thickness of eutectic Si particles, homogeneous structure, and minimization of casting defects in 2 wt.% Al-5Ti-1BAl-5Ti-1B added Al-12.6Si alloy plays a vital role in enhancing the hardness (71 HV), yield strength (YS, 126 MPa), ultimate tensile strengthTensile strength (UTS, 198 MPa).

Binder jettingBinder jetting of aluminum powderAluminum powder has progressively gained industry interest especially from automotiveAutomotive and aerospace for the fabrication of lightweight products. However, the interactionsInteractions between the polymeric bindersPolymeric binder and oxidative behavior of aluminum powderAluminum powder have not yet been extensively studied by researchers. Hence, this research focuses to understand the impact of different polymeric bindersPolymeric binder on the final quality of the fabricated sample through performing composition and porosity analyses. The resulting impurity levels and final density were evaluated to identify the most compatible polymer binder for aluminum powderAluminum powder. Five liquid binders were prepared and utilized to fabricate green state samples with the AlSi10Mg powder. The lowest level of impurities was obtained with the alcohol solvent-based binders whereas organic solvent-based binders, such as highly non-reactive thermoplastic fluoropolymer and cyanideCyanide-based synthetic polymer, and water-based binders were reported to deposit moderate to high binder residues on the samples after the debinding heat treatmentHeat treatment. The alcohol solvent-based binder provided the highest sintered density of 95.1%, while the PVA binder delivered the lowest sintered density. Hence, this research recommends the PVP binder as the most suited binder among the considered binders as it provided the highest densificationDensification with minimal chemical interactionsInteractions with the aluminum powderAluminum powder.

A framework for additive manufacturingAdditive manufacturing aluminum alloyAluminum alloys selection was developed to determine the preferred composition and process parametersProcess parameters from which to fabricate topology-optimized optical instrument housings and light-weighted freeform mirrors for the Compact Hyperspectral Air Pollution Sensor (CHAPS). In recent years, a number of high-strength laser powder bed fusionLaser-powder bed fusion aluminum alloysAluminum alloys have become commercially available, which are attractive for aerospace applications due to their high specific strength. Three aluminum alloysAluminum alloys were selected for a three-Round experimental comparison. Each Round used a down-selected subset of alloys and parameter sets (candidates) from the previous Round. Round 1 screened a wide range of laserLaser parameter sets for those that produced the highest density and tensile yield strength. Round 2 evaluated build quality using test geometries representative of CHAPS and assessed compatibility with post-processingProcessing, including optically black coatingCoating for the optical housings and nickelNickelphosphorus plating for the mirrors. Round 3 characterized anisotropyAnisotropy in tensile and thermal properties. A rating system was developed which involved assigning priority weighting for CHAPS-specific criteria and binning test results into scoring categories to give a comparison score for each candidate which was used in the down-selection between Rounds. The framework selection process enabled a comparison of the relative strengths and weaknesses of each candidate and resulted in the selection of Scalmalloy as the preferred alloy for CHAPS. The selected candidate was used to develop designDesign allowables for the topology optimization of CHAPS prototype housings, which were then fabricated.

The relationships between the microstructureMicrostructure and thermal behaviour of additively manufactured and cast aluminumAluminum A205, a recently developed Al–Cu–Mg–Ag–TiB2 alloy, were investigated. Microstructural characterizationMicrostructural characterization performed using scanning electron microscopy (SEMScanning electron microscopy (SEM)) indicated a significant difference in grain size between laserLaser powder bed fusion (LPBF) and cast specimens. Ultrafine round intercellular precipitates were observed in the LPBF structure, while intergranular precipitates were found in the cast structure. Trans-cellular TiB2 particles were observed in the LPBF structure, while accumulated intergranular TiB2 particles were found in the cast structure. Moreover, X-ray diffraction analysis revealed a higher fraction of precipitates in the LPBF specimen compared to the cast specimen. This was attributed to extremely high cooling rates which extend the solubilitySolubility of alloying elements in the matrix. The thermo-analytical study demonstrated a strong correlation between the microstructural scale and precipitate dissolutionPrecipitate dissolution kinetics of A205. The higher diffusion rate inherent in refined microstructuresMicrostructure facilitates the dissolutionDissolution of precipitates in the LPBF A205.

In the present work, we investigated the governing mechanism of grain refinementGrain refinement in AA3104 Al–Mn alloyAl-Mn alloys made by laserLaser direct energy deposition (DED) additive manufacturingAdditive manufacturing (AM). The microstructureMicrostructure development and phase transformationPhase transformation of DED AM AA3104 were studied by adding different concentrations of Ti, B, Ti–B mixture, and TiB2 particles as grain refinersGrain refiner. The transition from large columnar grains to fine equiaxed grains was achieved by Ti or Ti–B addition, but not by B or TiB2 addition. The study demonstrated that reactive additive manufacturingAdditive manufacturing may be a more effective way to refine grains than directly adding ceramic particles. The formation of Al3Ti plays the most critical role in grain nucleation during DED AM.

Increasing requirements to reduceReduce CO2 emissionsEmissions by using high scrap rates while maintaining the same high material properties represent a major hurdle that modern aluminum alloysAluminum alloys must overcome. Since classic aluminum alloyAluminum alloys systems are limited to one main alloying element, material improvementsImprovement to meet the requirements described above are limited. In this context, crossover alloysCrossover alloy—a new class of aluminum alloysAluminum alloys that is capable of combining beneficial properties of already existing alloys and alloy classes by advanced alloy designAlloy design—have recently gained increased attention in the scientific community. Industrial trials on 5xxx5xxx/7xxx crossover alloysCrossover alloy carried out by AMAG (AMAG CrossAlloy.57) additionally reveal an outstanding performance that is not limited to use in any specific industrial sector. This study provides an insight into the potential of CrossAlloys® for a wide range of applications.

For various products made of cast aluminum alloysAluminum alloys, such as automotiveAutomotive components and parts of household appliances contacting with a corrosive environmentEnvironment, increased corrosionCorrosion resistance is required. One of the ways to increase the corrosionCorrosion resistance of aluminum alloysAluminum alloys is anodizing. However, anodizing increases the cost of products and cannot be applied to bimetallic castingsCasting. Al–Ca alloys demonstrate good corrosionCorrosion resistance in an as-cast state together with excellent castability allowing to produce parts of complex geometry. In the Al–Ca system alloys, various alloying elements are used to achieve a good level of mechanical propertiesMechanical properties. In this paper, Al–Ca compositions containing Zn, Si, and Mn were analyzed in comparison with reference cast aluminium alloysAluminium alloys in salt spray and alkaline media. It is shown that Al–Ca alloys have a good potential for applications where high corrosionCorrosion resistance is a key characteristic.

Production of Al alloysAl alloy from End of Life (EoL) scrap is accompanied by increased Cu and Fe contents, as these cannot be economically removed from the meltMelt. Within the scope of this work, Cu- and Fe-containing alloy variants of AlSi7Mg0.3AlSi7Mg0.3, based on CALPHAD simulationsSimulation, were produced at a laboratory scale using gravity die castingCasting. Microstructural analyses and tensile tests of the as-cast state were carried out to characterize the influences of Cu and Fe on microstructural and mechanical propertiesMechanical properties. It is shown that Fe and Cu contents above the known limits of the standards can result in good mechanical propertiesMechanical properties. Hardness, yield strength, and tensile strengthTensile strength correspond well to the properties of the base alloy and cause only minor losses in elongationElongation.

One of the recent advancements in the field of high temperatureHigh-temperature aluminum alloys high strength aluminum alloysAluminum alloys is the development of the Al-Sc-Zr alloy. The addition of Sc and Zr in the AluminiumAluminium matrix results in trialuminide precipitationPrecipitation that imparts excellent coarsening resistance, making the alloy suitable for high-temperature application. In the early stages of solid–solid phase transformationsPhase transformation, the coherent microstructureMicrostructure is developed by maintaining the continuity between lattice planes and directions along the interface. These misfit strains significantly influence the shape and growth of trialuminides. The temperature dependency of misfit strain, which is often neglected in the theoretical simulationsSimulation of precipitate phases, is considered in the present work to investigate microstructural evolution and resulting strain and concentration field distribution during trialuminide precipitationPrecipitation using the phase-field method. Also, an assessment of the precipitation kinetics during Al3X (X = Sc, Zr) growth in the Al matrix with the help of particle size and energy variation-time graph is also done to get an insight into the precipitationPrecipitation mechanism.

We demonstrate that a small addition of a low-melting pointMelting point element such as Sn (0.02 at.%), within the impurity tolerances of commercial aluminum alloysAluminum alloys, to an Al-0.5Mn-0.3Si (at.%) model alloy, converts this non-heat-treatable (with negligible precipitation strengtheningPrecipitation strengthening) alloy into a heat-treatable (precipitationPrecipitation strengthened) alloy with high strength, creep, and coarsening resistance. The small Sn additions refine significantly the α-Al(Mn,Fe)Si-precipitate distribution, which is related primarily to the formation of Sn-rich nanoprecipitates at intermediate temperatures (~200 °C). At higher temperatures, these nanoprecipitates act as heterogeneous nucleationHeterogeneous nucleation sites for Mn-Si-rich nanoprecipitates—the quasi-crystalline precursors of the α-precipitate. We demonstrate that precipitationPrecipitation hardening by these Sn-modified α-precipitates is a highly efficient approach for designing creep-resistant aluminum alloysAluminum alloys.

Sustainable trends in the packaging industry market are leading us to the development of new aluminium alloysAluminium alloys, that enable to achieve higher mechanical properties. Use of circular materials and post-consumer recycled materialsPost-consumer recycled material are the approaches to reduce the carbon footprint of products. Several aluminium alloysAluminium alloys were developed for aluminium narrow strips, cast with a rotary strip caster, to produce slugsSlug for aerosol cansAerosol cans. The newly developed alloys provide constant mechanical properties during the manufacturing process of aerosol cansAerosol cans, a good transformation and high deformable and burst pressures of the aerosol cans. With increasing mechanical properties of aerosol can materials, it is possible to achieve a significant impact on lightweight of the final aerosol cansAerosol cans. Innovative approaches were used with use of a post-consumer recycled materialPost-consumer recycled material in different proportions in the casting and heat treatment process of aluminium alloysAluminium alloys to reduce carbon footprint of products in the packaging industry.

AluminumAluminum 6xxx6xxx extrusionExtrusion alloys are attractive candidates for use in automotiveAutomotive applications to decrease vehicle weight. In this study, Al–Mg–Si alloysAl-Mg-Si alloys (6xxx) were extruded into 3 × 90 mm strips on a pilot scale extrusionExtrusion press with processingProcessing conditions designed to produce either recrystallized or unrecrystallized microstructuresMicrostructure. The grain shape and crystallographic textureCrystallographic texture were characterized by electron backscatter diffraction (EBSDElectron backscatter diffraction (EBSD)) and mechanical anisotropyAnisotropy was measured by tensile and VDA bend testing conducted at 0, 45, and 90 degrees to the extrusionExtrusion direction. It was found that strength and fracture anisotropyStrength and fracture anisotropy were significantly affected by crystallographic textureCrystallographic texture and the distribution of second phase particlesSecond phase particles. The results were rationalized using considerations for the sequence of damage initiation, void growth, and void coalescenceCoalescence.

In consideration of developments in electric vehicleElectric vehicle production, lightweight materials such as aluminum alloysAluminum alloys have gained increased interest by the AutomotiveAutomotive Industry to diminish total weight of vehicles. Structural parts of automobiles such as car crash boxesCar Crash Box require high impact damping energy and high tensile strengthTensile strength properties. To this end, different alloy compositions for aluminum alloysAluminum alloys have been used to improve mechanical propertiesMechanical properties of metals. In this study, different aluminum alloysAluminum alloys such as 6082 and 6005 has been considered as test materials and finite element (FE) simulationsSimulation were carried out with FE software. Crash boxes were manufactured with aluminumAluminum extrusionExtrusion production method and subjected to compression tests. In order to observe mechanical propertiesMechanical properties, tensile tests were performed according to the extrusionExtrusion direction. Results of FE simulationsSimulation have been compared with experimental data. As a result of this study, it has been observed that similar FE results with experimental tests can be obtained.

Developing computational modeling for semi-solidSemi-solid aluminum alloysAluminum alloys with a solid network can help optimize advanced pressurized castingCasting processes such as die-castingCasting, squeeze castingCasting, twin-roll castingTwin roll casting (TRC), and semi-solidSemi-solid forging. However, a comprehensive numerical approach that can capture the coupled behavior between grain rearrangement and deformation of each individual grain remains a significant challengeChallenges. Inspired by recent synchrotron imaging work on deforming equiaxed-globular Al-Cu alloysAl-Cu alloys showing granular deformation mechanisms, this research uses the particulate discrete element methodDiscrete Element Method (DEM) in 3D to generate two numerical assemblies of primary aluminumAluminum grains. Two-sphere particles and polyhedral grains were adapted in DEM to effectively represent aluminumAluminum crystals in 60% solid Al–15Cu alloy sample and 82% solid Al–8Cu alloy sample at 583 °C, respectively. Burgers contact model is introduced to consider viscous interactionsInteractions between two grains at high temperatures. Contact model parameters are found by an iterative approach to reproduce the rheological response of compression experiments. Developments of 3D DEM simulationsSimulation verified by compression experiments under controlled drained closed die boundary conditions will be useful for exploring the relationship among deformation process parametersProcess parameters and strain localization phenomena of a bulk semi-solidSemi-solid with enhanced microstructural sensitivity.

Requiring a high strength and concurrently a high ductilityDuctility in materials is generally a demand for opposing properties in dislocation slip deforming materials, such as Al–Mg–SiAl-Mg-Si wrought alloys. However, these are essential mechanical propertiesMechanical properties for safetySafety parts in the mobility sector. While the strength of Al–Mg–SiAl-Mg-Si wrought alloys is mainly governed by the state and density of the secondary precipitates, the deformation behavior and ductilityDuctility are affected by both precipitates and crystallographic textureCrystallographic texture. The deformation during extrusionExtrusion leads to the formation of characteristic texturesTextures in the bulk, which are distinct to a plane-strain deformation, and a peripheral coarse grainPeripheral coarse grain (PCG) layer beneath the surface. This PCG layer can have a detrimental effect on the bending ductilityDuctility, which assesses the crashworthinessCrashworthiness. However, an appropriate textureTextures in the bulk can counteract the detrimental effect of PCG and increases the bending ductilityDuctility at high strengths. Subsequently, based on EBSDElectron backscatter diffraction (EBSD) investigations of bending deformed microstructuresMicrostructure, a way to enhance bending deformation capability in Al–Mg–SiAl-Mg-Si profiles is proposed.

The tearing resistance of AA7075AA7075-T6 sheet material was measured at room temperature and at 200 °C along different directions. Tearing resistance is characterized by the energy required to completely tear a specimen, with higher energies indicating greater tearing resistance. Specimens were tested at 200 °C for times no longer than would provide a retrogression heat treatmentHeat treatment, from which the full strength of the T6 condition may be recovered by a reaging heat treatmentHeat treatment. Tearing resistance is significantly greater at 200 °C than at room temperature, which promises improved deformation processingProcessing of AA7075AA7075-T6. The tearing resistance at 200 °C varies with direction relative to the rollingRolling direction. The tearing resistance is highest in the L–T orientation and lowest in the T–L orientation, by ASTM E871 specimen orientation designations. The significance of these results to the deformation processingProcessing of AA7075AA7075-T6 sheet at elevated temperatures will be discussed.

Cup drawing is an important sheet metal forming process and is affected by the anisotropic behavior of materials. This anisotropic behavior is influenced by the chemical composition as well as the heat treatmentHeat treatment process of materials. Therefore, the selection of proper chemical composition of the material is important for formabilityFormability studies. In this study, different aluminum alloysAluminum alloys such as 6082 and 6005 which were subjected to different heat treatmentHeat treatment processes have been considered as test materials and FE simulationsSimulation were carried out with Marc software. In order to observe the anisotropic properties of test materials, tensile tests were performed with 0, 45, and 90° according to the extrusionExtrusion direction, respectively. Hill anisotropic yield criterion was used to define the anisotropic behavior of materials during the finite element studies.

A356 alloyA356 alloy is widely used in rail transit and aerospace fields due to its excellent comprehensive properties. The refiner is called “flavor element” in aluminumAluminum industry, which plays an important role in improving the alloy microstructureMicrostructure and mechanical propertiesMechanical properties. In this paper, as-cast Al-3Ti-1B-1.5Ce master alloyMaster alloy was prepared by fluorideFluoride salt method. The optimum amount and holding timeHolding time were obtained by comparing the effects of Al-3Ti-1B-1.5Ce and Al-3Ti-1B on the microstructureMicrostructure and properties of A356 alloyA356 alloy. Results showed that the average grain size in A356 alloy modified by 0.6% Al-3Ti-1B was 153.73 µm, which was much smaller than that of A356 alloyA356 alloy with an average grain size of 1750 µm. The introduction of Ce element caused a better refining effect of the Al-3Ti-1B-1.5CeAl-3Ti-1B-1.5Ce refiner master alloyMaster alloy. When the addition of Al-3Ti-1B-1.5Ce master alloyMaster alloy was 0.4%, the average grain size, tensile strengthTensile strength and elongationElongation reached 145.96 µm, 213.9 MPa and 11.86%, respectively.

In this paper, an Al-5Ti-1BAl-5Ti-1B grain refinerGrain refiner for continuous rheo-extrusionContinuous rheo-extrusion forming and its effect on the microstructureMicrostructure and properties of A356 alloyA356 alloy is investigated. Phase and microstructureMicrostructure of Al-5Ti-1BAl-5Ti-1B were examined by XRD, SEMScanning electron microscopy (SEM), and EDS. Furthermore, the effect of Al-5Ti-1BAl-5Ti-1B on the microstructureMicrostructure and properties of the A356 alloyA356 alloy was studied. Results showed that the continuous rheo-extrusionContinuous rheo-extrusion can break the TiAl3 phase in Al-5Ti-1BAl-5Ti-1B alloy and promote the TiB2 particle to distribute uniformly. When the content of Al-5Ti-1BAl-5Ti-1B is 0.8 wt%, the refining effect was best. The grain size can reach 170 μm and A356 alloyA356 alloy obtained the optimum mechanical propertiesMechanical properties. The tensile strengthTensile strength, yield strength, and elongationElongation were 290 MPa, 237 MPa, and 8.5%, respectively.

The annealingAnnealing process during cold rollingRolling significantly affects the mechanical propertiesMechanical properties of cold-rolled 1235D aluminum alloyAluminum alloys sheets and their foil products. The effect of the annealingAnnealing process on the recrystallized structure and properties of 1235D aluminum alloyAluminum alloys cold-rolled sheets was studied. The results show that their tensile strengthTensile strength decreased with the increasing annealingAnnealing time, from 96 to 89 MPa at 500 °C for 5 to 240 min, the elongationElongation remained unchanged, though. The tensile strengthTensile strength decreased from 93 to 90 MPa with the increasing annealingAnnealing temperature from 440℃ to 560℃, while the elongationElongation also decreased, from 37.4 to 36.8%. The heating and cooling methods of the annealingAnnealing process have little effect on the tensile strengthTensile strength of cold-rolled sheets after being annealed. In contrast, slow heating and slow cooling are both beneficial for improving their elongationElongation but correspondingly reduced their tensile strengthTensile strength.

In this work, a modified Al–Si–Mg (A356) alloyA356 alloy was prepared by vacuumVacuum-assisted high pressure die castingHigh Pressure Die Casting processes (V-HPDC). To release residual stresses, various thermal treatment schemes over a wide range of temperatures between 120 and 350 °C were experimented to the as-cast V-HPDC alloy, in an effort of understanding the effect of thermal treatment on tensile properties of V-HPDC modified Al–Si–Mg (A356) alloyA356 alloy. The morphology of eutecticEutectic silicon has a sound effect on the tensile properties of the tested alloy. The content of magnesium-based intermetallic phase, their morphology, and distribution throughout the matrix affect the tensile properties as well. The reductionReduction in the strengths of the alloy treated at 350 °C for two hours should be at least attributed partly to the absence of the magnesium-based intermetallic phase. However, the presence of sufficient amount of magnesium intermetallic phase plays an important role in strengtheningStrengthening the alloy thermally treated at 200 °C.

The shape and the flow state of the liquid surface in molten aluminumAluminum have an important impact on the castingCasting and rollingRolling process of aluminum alloysAluminum alloys. Mathematical models of flow of liquid in twin-roll castingTwin-roll casting and rollingRolling of 5182 aluminum alloyAluminum alloys strip was establishedEstablished in this paper. The influence of different nozzle structures of distributors on the shape and the flow state of liquid in the molten pool was studied by numerical simulationNumerical simulation. The results show that changes in the inclination of the nozzle of the distributor, the height of the nozzle, and the depth of the distributor into the molten pool will affect the flow of liquid in the molten pool. With the increase of the depth of the distributor into the molten pool, the shape of liquid surface in the molten pool changes obviously, and the turbulent kinetic energy of the liquid surface in the molten pool decreases. The reasonable structural parameters of the distributor nozzle were obtained through research.

Investment castingInvestment casting of aluminum alloyAluminum alloys openOpen-pore foams requires high mold temperatures to ensure proper mold filling. The microstructural evolution of these foams is affected by the resulted slow cooling rate and the limited solidificationSolidification space due to their intrinsic geometry. In our study, solidificationSolidification and homogenizationHomogenization of investment-cast Al–Cu foams were investigated using cooling curve analysis, optical microscopy, scanning electron microscopyScanning electron microscopy (SEM), and energy dispersive spectroscopy. EutecticEutectic Al2Cu preferably precipitates around Fe-rich needle-like phases and just beneath the surface. The latter suggests that the last meltMelt to solidify in foam castingCasting is near the surface. Solution annealingAnnealing for 16 h at 535 °C was sufficient to homogenize the Al–3.8 wt.% Cu sample but insufficient for the Al–4.8 wt.% Cu. Moreover, a 1D DICTRA model was proposed to simulate the Cu microsegregationMicrosegregation. SimulationSimulation results agree with the experiments, and back diffusion was found to contribute slightly to homogenizing the as-cast microstructureMicrostructure during a relatively near-equilibrium cooling.

The global community has set a goal of carbon neutrality by 2050. Almost one-fourth of the global emissionsEmissions, attributed to direct emissionsEmissions from industrial processes, must be addressed by developing zero-carbon alternatives for each process, including the production of aluminumAluminum. Several companies and research institutions are working on aluminum electrolysisAluminum electrolysis using oxygen-evolving inert anodesAnode, and recent developments are reported to be quite promising. For existing smelters, carbon capture and sequestration may become a realistic alternative, depending upon the successful adaptation of the flue-gas system enabling increased concentration of CO2 in the flue gas. A third alternative is electrolysisElectrolysis of aluminumAluminum chloride, keeping chlorine and carbon in separate recyclingRecycling loops. This paper gives a review of the efforts to date, from industry and academia, to decarbonize the electrolysisElectrolysis of aluminumAluminum. The development of the largest part of the carbon footprintCarbon footprint, arising from the production of the electrical energy used from fossil sources, is also discussed.

PFCPerfluorocarbon (PFC) emissionsEmissions from aluminum smeltingAluminum smelting are characterized by two mechanisms, high-voltage generation (HV-PFCsPerfluorocarbon (PFC)) and low-voltage generation (LV-PFCsLow-voltage PFC). HV-PFCsPerfluorocarbon (PFC) are emissionsEmissions produced when a cell is undergoing an anode effectAnode effect, typically >8 V. Modern cell technology has enabled pre-bake smelters to achieve low anode effectAnode effect rates and durations, thereby lowering their HV-PFCPerfluorocarbon (PFC) emissionsEmissions. LV-PFCsLow-voltage PFC are the emissionsEmissions produced when the cell voltage is below 8 V. Lacking a clear process signal to act upon, LV-PFCsLow-voltage PFC can be difficult to treat. To tackle this issue, Alcoa has conducted sampling on individual electrolysis cellsElectrolysis cell, during which continuous process and emissionsEmissions data, as well as periodic bath samples, were collected. In the sampled cells, a variety of conditions were observed where LV-PFCsLow-voltage PFC were generated. Understanding what was occurring at the cell level allowed for the identification of opportunities for process improvementProcess improvement, both for the reductionReduction of LV-PFCLow-voltage PFC emissionsEmissions and cell performance.

Most aluminumAluminum smelters today report on their Perfluorocarbon (PFCPerfluorocarbon (PFC)) emissionsEmissions by a method that is derived from the IPCC Guidelines for National Greenhouse Inventories of 2006 or 2019. Often the default industry emissionEmissions factors have been employed (Tier 1/Tier 2), however, many companies are looking into acquiring plant specific factors (Tier 3). Hydro and Norwegian Institute for Air Research (NILU) have been testing a method of time-integrated air sampling where canisters are used to extract gas from different smelter locations that can later be measured by Medusa GC–MS. Sampling duration is determined by gas flowGas flow and canister size and the PFCPerfluorocarbon (PFC) detection limit is down to ambient air—making the method very applicable to low emitting smelters. Preliminary results from canister sampling deviate from 2006 IPCC Tier 2 slope estimation, whereby the measurementsMeasurement, a total PFCPerfluorocarbon (PFC) method, show a CO2eCO2e reductionReduction of about 28% compared to the estimation.

Heavy metalHeavy metals emissionsEmissions from the aluminiumAluminium industry are mainly carried from the plant through fugitiveFugitive particulate matterParticulate matter (PM) originating from the aluminium electrolysisAluminium electrolysis pot room. To evaluate the behaviour of metal-carrying PM, both airborne and settled PM from two different primary aluminium smeltersAluminium smelter have been characterized and analyzed for composition and particle size distribution, with special emphasis on heavy metalsHeavy metals and carbon. In addition, optical particle sensors have been placed at different elevations in one of the plants to determine the concentrations of different particle sizes in fugitiveFugitive PM. Metals such as Fe and Ni were primarily found as particles together with S and P on partly combusted carbon PM. Settled PM from both plants were generally coarser (mean = 32–39 μm) and had a higher Al:Na ratio compared with airborne PM, with a mean PM of 21–22 μm. The optical sensors measured PM100 concentrations at roof level in the plant 5–6 times higher than the PM10 concentration during fuming events such as anodeAnode shift operationsOperations.

Today, quantification of diffuseDiffuse dustDust emissionsEmissions from large production halls are often estimations based on relatively few spatially and temporally constrained manual measurementsMeasurement in ventilators, wall- and roof openings. Results are used to extrapolate an average operationOperations-related discharge throughout the year where considerable variation in both the quantity, duration, and location will rarely give a representative picture of the emissionEmissions situation over the year. A new generation of openOpen pathPath instruments for continuous dustDust monitoring are being developed by NEO Monitors AS. Its improved measuring technology based on a divergent laserLaser aims to significantly increase pathPath length capability while keeping the detection limit low. Stability, robustness, and general ease of use are also significantly enhanced. However, as with current laserLaser-based solutions, calibrationCalibration and verificationVerification relies on reliable gravimetric reference measurementsMeasurement, either in lab or at site installation. Data from existing laserLaser technology for shorter pathsPath is used to identify limitations and challengesChallenges related to emissionsEmissions monitoring that occur through the building’s ventilation openings in the ceiling. Gravimetric reference measurementsMeasurement have been carried out to verify the dustDust levels reported by the laserLaser installation.

Polycyclic aromatic hydrocarbons (PAHsPolycyclic Aromatic Hydrocarbons (PAH)) are naturally present in raw materials used as a binder in prebaked anodesAnode for electrolysisElectrolysis of aluminumAluminum. Green anodesAnode are baked to about 1200 °C through a cycle of 14–17 days where organic hydrocarbon volatiles contribute to the carbonization process. Off-gases contain volatile and semi-volatile organic components, which are further treated to reduceReduce environmental emissionsEmissions by techniques such as regenerative thermal oxidizers and dry or wet scrubbers. Still, prebaked anodeAnode production contributes to a noticeable part of the reported PAHPolycyclic Aromatic Hydrocarbons (PAH) emissionsEmissions in Norway. Samples of condensed hydrocarbon-based residues have been collected from an off-gas treatmentGas treatment facility and a set of analytical methods applied to determine the presence of different categories of aromatic hydrocarbons in these samples. Based on the results of the characterizationCharacterization, it was determined that the residue contains sulfur-substituted and polar aromatic hydrocarbons in addition to the PAHPolycyclic Aromatic Hydrocarbons (PAH)-16 routinely reported. It was concluded that future research should be dedicated to extending the range of PAHsPolycyclic Aromatic Hydrocarbons (PAH) that can be reliably determined, with particular emphasis on substituted species.

The dissolutionDissolution of aluminaAlumina in cryoliteCryolite is a complex process, and better understanding is needed to ensure stable cell conditions and high energy efficiency. Additions of cold powder result in freezing of bath that hinders dissolutionDissolution, and creation of raftsRafts. The current work aims to develop and demonstrate a CFDCFD Modelling framework in OpenFOAM for freezing of bath on a fed dose of aluminaAlumina, based on the volume of fluid (VOF) method, where appropriate source- and sink terms are applied. Essential features have been verified by comparison with a Stefan problem, while simulating the dose as a floating rigid object demonstrate that a larger layer of freeze increase the damping of its movement. When simulating the dose as an immiscible fluid, spreading will hinder enough freeze to be formed around the dose. Hence, the added source terms behave as intended, but improvementsImprovement on the alumina-bath interactions are needed.

Alumina injectionsAlumina injection are the most frequent discrete events occurring in aluminum reduction cellsAluminum reduction cell. During each feeding, a significant fraction of the mass injected will float and create a raftRafts composed of aluminaAlumina and frozen bath which hinders the dissolutionDissolution rate of aluminaAlumina. However, a small fraction of the aluminaAlumina sinks in the form of a cloud in the electrolyte which establish idealized dissolutionDissolution conditions. Specific investigations were performed to understand the fraction of particles in each specific state and the cloud patterns. An analog experimental setup is presented to observe the cloud at low temperature. Organic particles, cooled with liquid nitrogen, were injected in water. Each experimental injection performed was analyzed during the formation of the ice-particle raftRafts to determine the surface and the density of the cloud. The results are compared with experimental injections performed in molten cryoliteCryolite using a see-through cell to pinpoint the similitude and disparities.

Using a specific description of the heat transferHeat transfer and diffusion coefficients, general mass transfer theory is applied to data available in the literature to identify their respective dissolutionDissolution rate. The following calculations using data from the literature are then compared to experimental work performed under laboratory conditions using a gravimetric method to evaluate the dissolutionDissolution rate of alumina disks. The contrast between the data from our experimental work and the validation provided by the literature is assumed inherent to the morphology of the sample and the adequate description of the flow around it. The following discussions highlight the dominant factor affecting the mass transfer coefficients and pinpoint the theoretical challengesChallenges to overcome to achieve more precise relations for future works.

The market situation and environmental requirements suggest that the direct synthesis of Al–Si alloysAl-Si alloys in aluminium electrolysisAluminium electrolysis cell can help to increase added value and reduceReduce a total CO2 footprint of alloys. The aim of this paper was to determine the influence of SiO2 additivesAdditive on the process controlProcess control during the production of Al–Si alloyAl-Si alloys. The regulation of the process strongly depends on the electrical resistance of the electrolysis cellsElectrolysis cell, so we determined the electrical conductivityElectrical conductivity of the electrolyte using the DC four-point method. The measured electrical conductivityElectrical conductivity was a guide for determining the dosing rate of SiO2. Optimization of the reductionReduction process has been done with the process computer data and measuring the properties of the electrolyte with STARprobe™. The promising results of direct Al–Si alloysAl-Si alloys synthesis in AP18 industrial cells could openOpen a pathPath to a large variety of greener Al alloys produced by electrolysisElectrolysis process.

In this paper, the gas analysis methodGas analysis method was used to measure the current efficiencyCurrent efficiency of multi cells in different aluminum electrolysisAluminum electrolysis potlines, the measurementMeasurement operationOperations was standardized, and the influence of sulfur contentSulfur content of carbon anodesCarbon anode on the measured values was studied. The results show that the sulfur contentSulfur content in carbon anodesCarbon anode should also be introduced into the gas analysis methodGas analysis method as a correction factor in addition to the scaleless volume of Orsat gas analyzer. A systematic approach of gas analysis methodGas analysis method and a comprehensive correction coefficientCorrection coefficient formula were proposed. Using the standardized measurementMeasurement approach and the comprehensive correction coefficientCorrection coefficient formula proposed in this paper, the difference between the measured current efficiencyCurrent efficiency by gas analysis methodGas analysis method and the statistical current efficiencyCurrent efficiency from metal tapping was found to be less than 0.3%.

Based on the step cooling curve method, continuously varying cell constant (CVCC) method, observation method, and carbon block sodium expansion rate determination method, the effects of KFKF content on liquidus temperatureLiquidus temperature, conductivityConductivity, aluminaAlumina solubility,Solubility and electrolysisElectrolysis expansion rate of cathodeCathode were studied. The results showed that the liquidus temperatureLiquidus temperature decreased with the increase in KF content. For every 1% increase of KF, the liquidus temperatureLiquidus temperature decreased by about 1.83 ℃. The conductivityConductivity increased with the increase of superheat, and the average conductivityConductivity increased by 0.009 S/cm for every 1 ℃ increase in superheat. Under the same superheat, the conductivityConductivity increased by 0.033 S/cm for every 1% decrease in KF. Under the same superheat, KFKF content had little effect on the dissolutionDissolution rate of aluminaAlumina. The electrolysisElectrolysis expansion rate of the cathodeCathode carbon block increased with the increase in the KF content. The purpose of this work was to study the effect of KFKF content on the physical and chemical properties of aluminumAluminum electrolyte, and to provide a theoretical basis for the selection of appropriate electrolyte composition in aluminum electrolysisAluminum electrolysis industry.

The gases generated at the electrolytic cells (or pots) of modern aluminumAluminum smelters are collected with a network of ducts that connect each of the pots to a scrubber in order to keep the overall emissionsEmissions to targets that are below regulatory limits. This pot ventilation has also an effect on the cell thermal balanceThermal balance and minimizes the exposure of workers to the pollutants from the pots. This paper explains the fundamentals of this ventilation process and describes a simplified approach for a quick verificationVerification of the gas flowGas flow at each pot. The paper also proposes a procedure for balancingBalancing the pot flows, which is the most basic practice for the optimum performance of the pot ventilation system.

Assessment of acid dew pointAcid dew point in industrial off-gasOff-gas has become increasingly important with strategiesStrategy for heat recoveryRecovery and the use of more concentrated gas compositions. Several approaches to acid dew pointAcid dew point assessment make use of glassware not compatible with the high fluorideFluoride concentrations found in unfiltered gas. In this work, a new and simplistic approach to acid dew pointAcid dew point assessment is evaluated side by side with conventional methodology. The new approach captures SO3 in the gas as sulfateSulfates onto a solid NaCl trap. Interference from SO2 is avoided since it passes through the NaCl trap unreacted. The trap is then dissolved in water for direct analysis by ion chromatographyIon chromatography. The importance of isokinetic sampling was evaluated, and no significant difference in results was observed. This suggests that the acid droplets are small. The method is shown to be promising for acid dew pointAcid dew point assessment in industrial off-gasOff-gas.

SO2 is one of the main sources of acid rain and air pollution. Semi-dry sorbent injection, using powdered alkaline sorbents, is an effective means of removing SO2. Since no costly additional equipment is needed, the operating cost is lower, and it is a more economical and efficient process compared to wet and dry desulfurization processes. The reaction between sorbent (hydrated lime, Ca(OH)2) and SO2 is dominated by the adsorption step. In this study, a mathematical model has been developed to simulate the lab-scale desulfurization reactor employed for the low-temperature gases containing low SO2 concentration coming from the electrolysis cellsElectrolysis cell used for aluminumAluminum production. A parametric study was carried out in order to examine the effects of certain parameters, such as inlet SO2 concentration, sorbent flow rate, and relative humidity of the gas on the desulfurization efficiencyEfficiency. The model and some of the results are presented in this article.

A mathematical model has been developed to reproduce the tridimensional interface between bath and metal in an electrolysis cellElectrolysis cell. In the last year, the mathematical model has been adapted to consider alumina raftsAlumina rafts movements in tridimensional coordinates. To reproduce a bath-metal surface, the wave equation was solved around three main phenomena known to occur in operating pot. Specific solution includes strong Lorentz force at the edge of the cell, natural resonance of the geometry, and impulse from perturbation. Among the geometrical challengesChallenges inherent to such improvementImprovement, it was necessary to properly introduce concepts such as “flow”, “interfacial forces”, and “buoyancy force”. Hence, the model uses interfacial phenomena to reproduce the movement of alumina raftsAlumina rafts at the bath-metal interfaceBath-metal interface. The potential of such tracking is shown in different cell conditions. This paper details the scope of the modifications applied to the model, describes in detail the step used to characterize both interface and raftsRafts and shows the raftRafts tracking potential for industrial application.

Electrical preheatingPreheating of aluminium electrolysisAluminium electrolysis cells using coke and/or graphite is a delicate process, which has a significant impact on cell life. Cell preheatingPreheating is evaluated by many factors such as the heat-up rate, the final cathodeCathode surface temperature distribution, anodic current distributionCurrent distribution, and longevity of cathodeCathode life [1]. Hence, a better understanding of the cell behaviour is required to optimise this critical phase. In this work, electrical, thermal, and displacement data have been measured on a cell during the preheatingPreheating period. Those measurementsMeasurement were then used to calibrate a quarter-cell model, which includes a transient thermo-electro-mechanical weakly coupled analysis, developed using ANSYS ™. The results obtained are in good agreement with in situ measurementsMeasurement and allow a better understanding of the anodic current distributionCurrent distribution, cathodeCathode surface temperature, baking levelBaking level of ramming paste, and stress level distribution in the cathodeCathode/lining, which are critical information for further optimisation.

A mathematical model coupling 3D electrical current distributionCurrent distribution, magnetic fieldMagnetic field and magnetohydrodynamic (MHDMagnetohydrodynamic (MHD)) behaviour of aluminium electrolysisAluminium electrolysis cell is presented. COMSOL Multiphysics®COMSOL Multiphysics® is used as a software tool to develop the present model. Implementation of electrical current carrying busbarsBusbar using line current source elements and evaluation of the MHDMagnetohydrodynamic (MHD) with the help of shallow-water equations method allow for a quick and robust parameter estimation. Sensitive modellingModelling details parameterization, and automated report generation features of the model provide an easy-to-use solution for preliminary designDesign evaluation. The modellingModelling results were compared with 3D COMSOL model developed before and validated with the measurementsMeasurement. Several simulationSimulation scenarios are presented in this paper showing the capability of the model to estimate the influence of the aluminiumAluminium cell constituents on the MHDMagnetohydrodynamic (MHD) behaviour of the cell.

At Aditya AluminiumAluminium, the average pot lifePot life is about 2000 days, pot reliningPot relining contributes approximately 2.1% of total production cost. To avoid the risk of pot failurePot failure, an average of 55–60 pots relining/year are planned out of 360 pots. Further, to reduceReduce failure, an in-house pot lifePot life estimation method was developed, which helped in planned pot stoppage. Firstly, pots were prioritized based on the pot age, ironIron & silica, side shell temperatureSide shell temperature (SST), Current EfficiencyCurrent efficiency and specific energySpecific energy consumption. These factors were assigned with individual weightage, which helped in pots shut down, further pot autopsy was performed for validation. A strategyStrategy was adopted for measuring regular SST, observing ironIron/silica pick-up, and Fe/ Mn ratio. Moreover, forced cooling regulation, and selective collector bar cutting were adopted to extend pot lifePot life. These methods helped Aditya AluminiumAluminium establish a global benchmarkGlobal benchmark among other modern smelters by achieving a pot failurePot failure rate ~0.6% since inception.

In March 2020, Aluar reduced its production. Two potlines with different technologies were halted within two weeks. Metal was left in the pots in order to preserve the cathodeCathode conditions during stoppage, so the repair procedure for the restart consisted in cleaning the metal surface, sidewall repairing and gas preheatingPreheating. The restartup of AP22 pots in Potline C was successfully accomplished six months later, with no incidents and a low early failure rate. Two years after, a pre-existed failure mode was identified during the restart of end-to-end al20 pots in Potline B. As a result, a higher amount of pots could not survive. This paper highlights the experience gained from a planned but necessary shutdown of 344 pots together with the challengesChallenges involved, not only in restarting two different potlines in a completely diverse context but also in the strategic criterion proposed for a pot restart in each case.

In February 2022, Albras had a potline freeze due to a power outage, shutting down 223 pots (the number of pots operating at the time). After 5 months, Albras was able to return 100% of the pots to operationOperations and production levels are back to normal. The early failure rate was a record low of 5% when considering a restart under such conditions, with only 12 failures. During the restart campaign, there were few thermal excursions above 1000 °C (daily average at 5.5). Average acidity was kept below 4% during the first 5 days of pot operationOperations. Originally expected to end in late November, the work was concluded in July, four months in advance, without any safetySafety incidents. The aim of this work is to describe the steps leading to what has become the most successful restart in Albras’ history in terms of schedule completion, success rate, process consistency, operational stability, and human capital development.

Retrofitting older aluminum reduction cellAluminum reduction cell line is an effective way to extend the productive life of an aluminumAluminum smelter. With the modification of busbarBusbar system, cathodeCathode lining design,Design and superstructure designDesign, the GP320GP320 aluminum reduction cellAluminum reduction cell can achieve the target of both current creepCurrent creep and energy saving. In July 2020, a retrofitted GP320GP320 cell line was started up (which was initially designed in 2002 and started up in 2003), and the current has been increased to 340kA. Until June 2022, all the cells are operating in stable, high-efficient condition. The retrofit has reached the designDesign target and has shown a great example for the future of older cell lines.

Shenyang AluminumAluminum and Magnesium Engineering and Research Institute Co. Ltd (SAMI) has carried out a series of technical research and experiments since 2015 to develop a more environmentEnvironment-friendly and energy-efficient aluminumAluminum reductionReduction technology. By adopting the technical route of improving MHDMagnetohydrodynamic (MHD) stability while reducing cathode voltage dropCathode voltage drop, SAMI's New Conceptual CathodeCathode Technology namely NCCT Technology has been developed. In 2019, this technology has been applied and verified in the Indonesian INALUM aluminumAluminum smelter’s upgrade project. Since then, an expanded industrial test was implemented on two SY500 potlines in 2021 and a newer version of NCCT Technology has been developed, called NCCT+ TechnologyNCCT+ Technology. Statistical data over the past year demonstrates that energy consumption of NCCT Technology is <12,300 kWh/t Al, while that of the NCCT+TechnologyNCCT+Technology is <2,200 kWh/t Al. Both these technologies provide strong technical support for the aluminumAluminum industry to upgrade existing reductionReduction cells for better carbon emissionEmissions.

Since 1996, Shenyang AluminumAluminum and Magnesium Engineering and Research Institute Company Limited (SAMI) has developed a series of aluminumAluminum reductionReduction technologies, the SY series, ranging from 160 kA, 190/200 kA,230/240 kA 280 kA, 300 kA, 350 kA to 400 kA. In 2009, SAMI developed the 500 kA reductionReduction technology called SY500, and since then SAMI has been continuously improving this technology and has applied it in the engineering of new aluminumAluminum smelters. The paper introduces the development of the first, second and third generation SY500 potline technology, systematically analyzes breakthroughs of new technologies adopted by SY500 pot technologySY500 Pot technology, such as the New Conceptual CathodeCathode Technology (NCCT), New Conceptual BusbarBusbar Technology (NCBT), Network BusbarBusbar Technology (NBT), etc. The SY series potline technology has been validated for its excellent technical and economic performances and become the most widely used reductionReduction pot technology.

In Emirates Global AluminiumAluminium (EGA), the first pots were started up in 1979 in its Jebel Ali smelter (then called Dubai Aluminium—DUBAL), using Kaiser P69 cells at an amperage of 150 kA. In 2014 EGA started up its flagship, homegrown DX+ UltraDX+ Ultra technology at 450 kA. In 2017 DX+ UltraDX+ Ultra was upgraded targeting operationsOperations at higher amperages, eventually reaching 480 kA by 2019. Now, in 2022, EGA succeeded in starting up DX+ Ultra technology at 500 kA500 kA. This was done on 5 pots in its Jebel Ali smelter research and development demonstration section called Eagle. This paper aims to describe some of the adjustments made from the previous generation of DX+ UltraDX+ Ultra technology to enable the additional 20 kA amperage increase and start up the pots at 500 kA500 kA. It also details some of the related challengesChallenges and results from the preheatPreheat, start-upStart-up and early operationsOperations periods.

The growing stockpiles of bauxite residueBauxite residue and associated environmental hazards require a sophisticated process flowsheet for sustainable residue management and value recoveryRecovery. Considering the association of multiple elements (Fe, Al, Si, Ca, Ti, V, Sc) within bauxite residueBauxite residue, metal extraction is of prime interest. The complex association of different elements and physical and chemical characteristics makes the extraction and purification process expensive and challenging. The present study focuses on developing a novel hydrometallurgical flowsheet for the subsequent recoveryRecovery of base metals and critical elements from bauxite residueBauxite residue. The major elements present in bauxite residueBauxite residue are recovered as high-purityPurity magnetiteMagnetite, titaniumTitanium dioxide, and aluminaAlumina. At the same time, critical elements (such as V and Sc) are recovered in the liquid stream generated after the recoveryRecovery of base metals.

The three-stage production chain of aluminumAluminum from ore to castingCasting is complex and consumes massive amounts of energy and input materials. The process also results in undesirable by-products, such as bauxiteBauxite tailingsTailings and bauxite residuesBauxite residue or red mudRed mud. From a holistic perspective, the overall sustainabilitySustainability of the aluminumAluminum industry is dependent on several factors that go beyond the recent focus on the low carbon drive across the companies and regions. Globally, some 3 billion tons of bauxite residueBauxite residue (red mudRed mud) are now stored in massive waste ponds or dried mounds, making it one of the most abundant industrial wastes on the planet. AluminaAlumina refining plants generate an additional 150 million tons each year. The industry produces 0.5–2 tons of bauxite residueBauxite residue per ton of aluminumAluminum. Although actively globally pursued, the current utilization of bauxite residuesBauxite residue is less than 4%. In the author’s published analysis, mitigation and utilization of bauxite residueBauxite residue are the number one sustainabilitySustainability-enhancing factor. The objectives of this paper are: 1. Review of bauxite residueBauxite residue utilization status 2. Assess the feasibility and prospects of current efforts underway 3. Suggest economic incentives to encourage higher utilization.

Spent pot lining (SPLSpent Pot Lining (SPL)) is one of the largest solid wastes generated from the primary aluminiumAluminium production process. Around 23 kg of SPLSpent Pot Lining (SPL) is generated per tonne of aluminumAluminum. ALBA is the largest aluminumAluminumproducing smelter in the world outside of China with an annual production of 1.56 million tonnes of aluminumAluminum (2021), the amount of SPLSpent Pot Lining (SPL) generated is becoming very significant. SPLSpent Pot Lining (SPL) is classified as hazardous material contaminated with cyanideCyanide and fluoridesFluoride. The traditional way of handling such waste is either stockpiling around smelters facility or landfilling, which is not the best sustainable solution. ALBA has taken the initiative to construct its own one of a kind SPLSpent Pot Lining (SPL) treatment plant through its partnership with Regain Technologies to process and detoxify its SPLSpent Pot Lining (SPL) and convert it into useful feedstock for other industries such as the cement industry. This paper discusses the journey of Alba toward its sustainable solution of converting the SPLSpent Pot Lining (SPL) into a useful valuable product called HiCAL30HiCAL30. Moreover, this paper will focus on the process flow, detoxification heat treatmentHeat treatment process as well as the final product specification and usages.

Spent potlining (SPLSpent Pot Lining (SPL)) is a hazardous waste produced by aluminumAluminum smelters. It is classified as a hazardous waste due to its contamination with fluoridesFluoride and cyanidesCyanide and its reactivity with water, generating explosive gases. After being industrially and hydrometallurgically treated by the Low Caustic Leaching and Liming (LCL&L) process, the refractory part of SPLSpent Pot Lining (SPL) becomes an inert, non-hazardous material, called LCLL Ash. The cement industry is a major emitter of greenhouse gases. One of the best options for reducing the carbon footprintCarbon footprint of concrete is the use of supplementary cementitious materials or fillers to replace part of the cement in the concrete. This article presents the conditions that make LCLL Ash a suitable and value-added material for the cement industry. The results presented were obtained over the past four years as part of an R&D project at the Ecole de Technologie Superieure (Montreal) and UniversiteUniversities Laval (Quebec), with the support of Rio Tinto and Ciment Quebec.

Tetra PakTetra Pak packages which are multi-layered composite materials (approximately 75% cardboard-celluloseCellulose, 20% LDPE and 5% Al by weight) facilitate the distribution of particular food products and aid to preserve some food properties for a longLong time. In this study, experiments were proceeded to separationSeparation of the layers of Tetra PakTetra Pak aseptic packages efficiently from each other and their recyclingRecycling. Hydropulping process were carried out for the separationSeparation of the cellulosesCellulose part which is paper for this material; then, hydrometallurgical and pyrometallurgical treatments were followed through for partition of polyethylene and aluminumAluminum (PEAl) fractions from each other. In hydrometallurgical pathway, PEAl samples were put in vegetable oil, observed according to increasing temperature, time and solid/liquid ratio parameters, at the end the LDPE and Al phases were purified. The pyrometallurgical studies (pyrolysis) were carried out with various time and temperature combinations, and efficiencyEfficiency of Al recoveryRecovery from PEAL fraction were investigated.

The Pyrotek MCR Group has developed a unit, the Electromagnetic Deep Filtration (EM-DF) system, that successfully primes multiple Ceramic Foam Filters (CFF) for filtration in casthouse and foundry operation using patented electromagnetic technology. Regular gravity-primed filter boxes are restricted by metal head for a certain filter grade and the number of filters used; most use a single filter and require a substantial metal head. The EM-DF system enables multiple filters with identical or dissimilar grades to be used at standard launder metal levels. Consistent priming of all filters has also been achieved, expecting to deliver greater and more consistent filtration efficiency, making the filtration process more reliable. This communication presents the results from conducted industrial trials using triple stack 50 grade Pyrotek Sivex CFFs with the size of 24.5″, 23.7″ and 23″. The system’s performance, productivity, safety, and reliability are discussed.

Assessing metal cleanlinessMetal cleanliness of aluminumAluminum meltsMelt is critical for product quality control, as well as for process optimization. PoDFAPoDFA is the current standard method for assessing aluminumAluminum cleanliness but has limitations in speed and costs due to its manual image processingProcessing. The Automated Metal CleanlinessMetal cleanliness Analyzer (AMCA) method was previously demonstrated to produce cleanliness indicators highly correlating to the main cleanliness indicator of industrial PoDFAPoDFA analyses on the same samples. In the present work, the features of the AMCA method were expanded, introducing quantitative inclusionInclusions characterizationCharacterization and enhanced detection features. The results were systematically benchmarked against industrial PoDFA-derived cleanliness data. The results confirm the equivalence of the total particle area and provide moderate differentiation of inclusionInclusions types. Thereby, AMCA shows potential to be used as an alternative to PoDFAPoDFA, deriving cleanliness data of aluminumAluminum samples for generating extensive process data at superior cost-scaling and minimized human biases.

Controlling metal cleanlinessMetal cleanliness in primary and secondary aluminumAluminum production is critical for ensuring quality in commercial sales and for effective process optimization. Solidified aluminumAluminum meltMelt samples are today typically analyzed using establishedEstablished techniques such as LiMCA and PoDFAPoDFA, however, these techniques rely on heavy and expensive equipment, extensive running times, and high heterogeneity of the results. The primary bottleneck of PoDFAPoDFA analyses, the current standard approach, is the manual analysis of meltMelt micrographs by human operators. In the present study, an image analysis platform based on a machine learningMachine learning algorithm capable of quantifying contaminants in PoDFAPoDFA micrographs was developed and tested. Machine learningMachine learning models enable improved performance in heterogeneous datasets compared to common image analysis techniques using minimal computational resources and are envisioned to enable superior cost-scaling in metal cleanlinessMetal cleanliness assessments. Future implementations will expand on the quantitative differentiation of relevant inclusionInclusions types.

White dross is a hazardous waste generated during the primary production of aluminum (Al) which consists of a heterogeneous mixture of different oxides and metallic Al in the form of large flakes, lumps, particles, and dust. Due to the heterogeneity of the dross, sampling is challenging. A sampling tool with step-by-step procedures for its use has previously been introduced, with recommendations for how to pulverize and analyze different fractions of the dross using X-Ray Diffraction (XRD). In the present study, Electron Probe MicroAnalysis (EPMA) scans of white dross samples collected from the holding furnace in an Al casthouse during the production of Al alloy 5182 (AlMg4.5Mn0.4) and 6016 (AlSi1.2Mg0.4) have been quantified and referenced to XRD analysis. The obtained results suggest that the image analysis method can quantitatively assess the influence of various process parameters on dross characteristics and thereby contribute to optimizing industrial furnace operations aiming to reduce dross formation.

Presence of non-metallic inclusionsNon-metallic inclusions (NMIs) reducesReduce surface quality and mechanical propertiesMechanical properties of aluminumAluminum products. The development of good NMIs removal practices relies on the understanding of inclusionInclusions behaviors with respect to separationSeparation and agglomerationAgglomeration particularly in the turbulent flow. In the scenario of electromagnetically induced recirculated turbulent flow, the concerned behaviors of inclusionsInclusions with different sizes have rarely been investigated experimentally. In the presented study funded by AMAP Open Innovation Research Cluster, reference materialsReference material were prepared with uniformly distributed NMIsNon-metallic inclusions (SiC and MgAl2O4) via an ultrasoundUltrasound-involved castingCasting route. Reference materialsReference material were charged into an aluminumAluminum meltMelt where turbulent flow was promoted via electromagnetic force. Microscopical analysis shows non-significant agglomerationAgglomeration tendency of SiC, MgAl2O4, and TiB2 inclusionInclusions. Time-weight filtrationFiltration curve, PoDFAPoDFA, and Spark Spectrometer results suggest a strong dependence of separationSeparation rate on particle size. Analytical models were establishedEstablished to estimate the collision rate of particles and to evaluate separationSeparation probability of different sized particles.

LaserLaser-induced breakdown spectroscopy (LIBS)LIBS provides a way to study aluminumAluminum meltMelt dynamics. In the present work, liquid-phase LIBS analysis is used to study the behavior of group-II metals in Al–Mg alloys. The effects of Sr and Ca microalloying in high-Mg alloys suggest that these elements have an inhibiting effect on Mg oxidationOxidation. It is shown that adding the microelements Sr and Ca in an induction crucible significantly reducesReduce the Mg partial pressure at typical process temperatures. It is believed that Sr and Ca form a barrier that reducesReduce the vaporization of Mg through the surface.

In casthousesCasthouse, water vaporWater vapor has longLong been considered a source of high hydrogen contentsHydrogen content in aluminumAluminum meltsMelt. Moisture levels are usually highest in melting and holding furnaces, where H2O contents of up to 18 vol% occur due to the combustion of natural gas with air. In the case of oxyfuel burners, contents of even more than 60 vol% are theoretically possible. To avoid defects such as annealingAnnealing bubbles or grain porosity in the subsequent production steps, the absorbed hydrogenHydrogen must be reduced to a minimum by degassing treatments. To gain a better understanding of the interactionInteractions between liquid aluminumAluminum and water vaporWater vapor, the hydrogenHydrogen absorption of aluminumAluminum-magnesium meltsMelt under atmospheres with varying water vaporWater vapor contents of 0–90 vol% at around 700 °C (1300 °F) is investigated in this work. Furthermore, the influence of H2O on the oxidationOxidation behavior is also examined.

Salt fluxesSalt flux with fluorideFluoride additions are necessary for the treatment and recyclingRecycling of contaminated or oxidized aluminiumAluminium scrap. This study aims to investigate the effect of cryoliteCryolite additions on the thermal properties and the coalescenceCoalescence efficiencyEfficiency of a NaCl–KCl salt fluxSalt flux mixture. Thermodynamic calculationsThermodynamic calculation were carried out to examine the phase diagram of the salt mixture as the cryoliteCryolite content increases. The study of the melting properties of the salt was carried out by means of differential scanning calorimetryDifferential scanning calorimetry. The coalescenceCoalescence efficiencyEfficiency of the salts was assessed by re-melting coated aluminiumAluminium chips. The experimental results show a decrease in the liquidus temperatureLiquidus temperature as the cryoliteCryolite content increases; this differs from the thermodynamical calculations. For cryolite contents up to 3 wt%, higher cryoliteCryolite content in the salt leads to higher coalescenceCoalescence of re-melted chips. However, the coalescenceCoalescence differences observed between the recyclingRecycling products for cryoliteCryolite contents of 3% and higher were minor.

By switching from fossil to hydrogenHydrogen fuel in melting furnaces, the CO2 footprint of a cast houseCast house in the aluminiumAluminium industry can be reduced considerably. However, using hydrogenHydrogen instead of fossil fuel will increase the water vapour concentration in the furnace atmosphere and likely change the oxidationOxidation behaviour of molten aluminium alloysAluminium alloys. A series of tests have been performed where Al–Mg alloys were melted and normally held for 4 h in different atmosphere compositions due to variations in fuel type and burner set-up. The results show that combustion of hydrogenHydrogen in an air–fuel configuration gives more oxidationOxidation on liquid Al–Mg alloys than combustion of hydrogenHydrogen in an oxy-fuel configuration. The tests also show that as little as 5% CO2 in the furnace atmosphere significantly suppresses oxidationOxidation. The suppressing effect of CO2 was greater on alloys with 4.7% Mg than on alloys with 3.1% Mg.

The need to maximize the efficiencyEfficiency in post-consumer aluminumAluminum scrap recyclingRecycling processes is continuously rising in order to achieve sustainable industrial implementation of circular economy practices. The present work investigated the optimization of pre-heating process during the recyclingRecycling of Used Beverage Cans (UBCs) in a multi-chamber furnaceMulti-chamber furnace. In particular, aiming to predict the UBC temperature distribution during pre-heating, a numerical model of an industrial furnace was developed considering conduction, convection, and radiation mechanisms for heat transferHeat transfer. A laboratory electric resistance furnace was used to measure the UBC delacqueringDelacquering degree as a function of the temperature. The obtained correlation (Temperature – Delacquering Degree) was then incorporated into the numerical model rendering it a useful tool for evaluating the delacqueringDelacquering process. The model results were validated by industrial-scale trials. Finally, the dependence of the UBC delacquering on various industrial-scale process parametersProcess parameters was examined.

It is a novel green method of meltMelt aluminum alloysAluminum alloys that no chemical resolvent and fluxes were used. Currently, the harmful gases including Chlorine (Cl), Florine (F), and other harmful substances were exhausted during aluminumAluminum meltMelt. The discharge of the solid drossDross including Cl and F has also been limited strictly due to environmentEnvironment protection. In order to reduceReduce the discharges and resolve the problemsProblems of environmental pollution in aluminumAluminum industries, it is invented that the high pure argon gas by use of an artificial intelligenceArtificial Intelligence (AI) control systemControl system goes through a distinctive refractory structure with internal micropores, which distributed on certain regular patterns and included nanoparticles with rare earth elementsRare-earth element in the bottom of meltMelt furnace. Al liquid under the atmosphere is kept at a dynamic balance state with inert gas bubbles in microscale from starting melting to end of castingCasting. The ingots from the meltMelt processingProcessing can meet current requirements in aluminumAluminum industries. The hydrogen contentHydrogen content was less than 0.3 ml/100 gAl, and the total drossDross reduced 50% or higher than 50%. Burning loss of metal decreased 0.2–0.8% and energy cost (natural gas) reduced 10% per ton aluminum alloyAluminum alloys. If this system would be applied with a common degasser and filter system, H content in Al liquid could be controlled at less 0.05–0.10 ml/100 gAl level. The purityPurity of the Al liquid arrives at a higher grade than some conventional meltMelt processingProcessing and can realize the green melting and AI digital control characteristic under the industrial conditions.

TST is a California-based company leading the way in manufacturing aluminumAluminum ingot, billet, and slab worldwide for over 76 years. TST is committed to providing the highest quality products. TST is committed to continuous improvementsContinuous improvement in its casthouseCasthouse operationOperations and has installed the world’s first and only permanent magnet-based pump, MagPump™, from Zmag (Japan). MagPump is designed to be a direct replacement for traditional mechanical pumps in side well (multi-chamber) furnaces without requiring furnace modification. MagPump is powered by zPMC™ (Zmag Permanent Magnetic Circuit) which generates virtual impellers to pump molten aluminumAluminum. Unlike mechanical pumps, MagPump does not have physical impellers and therefore is a nearly hands-free system, with no consumable parts, and reduced downtime. MagPump is also capable of other applications such as gas injection (e.g., Chlorine, Nitrogen, Argon) and scrap submersion. Operator safetySafety has been increased as the necessity to approach the pump well has been minimized.

AluminiumAluminium is applied in food packaging due to its preservative capability. However, food residueFood residue and the fact that most packaging is thin gauge material, 50–250 µm, makes recyclingRecycling challenging. In Northern Europe, processed cheese, caviar, and mayonnaise are popular items stored in toothpaste-shaped tubes. This paper focuses on the evaluation of the recyclability of these Al tubes from the aspect of tube thickness, user habits, food residueFood residue, benefits of pre-treatment, all in regard to yield. Food residueFood residue reduced the yield from around 88% (non-used empty) to 57% (with 3% food residueFood residue), and down to 34% (with 16% food residueFood residue). For comparison, the influence of beverage residue on yield was also studied. The influence of beverage residue is minimal, even neglectable after drying the can. The results also show that the influence of food residueFood residue on the yield is larger than that from decoatingDecoating. The producer change in tube wall thickness did not influence the recyclingRecycling yield considerably. However, a thinner tube makes it easier to be emptied. This together with that thinner tube uses less Al to protect the same amount of food implies that the thinner tube can be regarded as more environmentally friendly.

Recent studies using HR-TEM, (High-Resolution TransmissionTransmission Electron Microscopy) at BCAST, Brunel University, London, on the mechanism of nucleation of a­aluminiumAluminium on TiB2 in commercial high-efficiencyEfficiency grain refinersGrain refiner have shown that efficiencyEfficiency as measured by the Opticast Nucleation test can be directly related to the extent to which the TiB2 particles have successfully formed a monoatomic layer of TiAl3 on their basal plane. This factor was found to be predominant over other factors such as particle size distribution and average particle size. As a result of this research, it is now possible to produce a range of ultra-high efficiencyEfficiency grain refinersGrain refiner which enable addition rates to be further reduced to levels as low as 0.15 kg/t resulting in higher cost savings and the particle count being significantly reduced in the liquid metal leading to as cast metal quality being improved.

In cast aluminiumAluminium products, small equiaxed grains reduceReduce the risk of hot tears and shrinkage porosities by facilitating the liquid feeding in the interdendritic liquid. Although grain refinementGrain refinement in aluminium alloysAluminium alloys is well known and widely used, grain size control is still not always guaranteed industrially. This depends largely on the nature and fabrication quality of the grain refinerGrain refiner rod. In this work, we developed a cellular automaton modelCellular automaton model to establish a clear link between the grain refinerGrain refiner type/nature and grain refining efficiencyEfficiency while accounting for the principal physical phenomena affecting grain refinerGrain refiner performance: grain refinerGrain refiner nature, nucleant size distribution, recalescence, solute suppressed nucleation zone. At TMS2020 [1] we experimentally highlighted the inconsistencies in grain refinerGrain refiner performance between different producers and in batches of the same producer. This model helps in qualifying grain refinersGrain refiner and would serve as a prescriber for designing next-generation grain refinersGrain refiner with superior efficiencyEfficiency.

Ultrasonic processingProcessing can be performed without a vibrating probe by electromagnetic induction with a suitable frequency where resonance conditions can be establishedEstablished. This contactless method is suitable for high-temperature or reactive metal alloys providing purityPurity of the meltMelt and durability of the equipment. HydrogenHydrogen bubbles coming out of solution grow by rectified diffusion, and larger bubbles escape from the top surface leading to degassing. Violent collapses of the remaining smaller bubbles help grain refinementGrain refinement. In this study, the application of a contactless ‘top-coil’ device to continuous castingContinuous casting via a launder is considered. Resonance is achieved by the positioning of baffles on either side of the coil. Electromagnetic forces also cause strong stirring, increasing residence time. The process is modelled using time domain and frequency domain methods, and results for the proposed setup are compared with data obtained for the immersed sonotrode. Accuracy and sensitivity to process and model parameters are discussed.

In the direct chill castingCasting of aluminum alloysAluminum alloys, the stripe-shaped segregationSegregation called channel-type segregationsSegregation is formed in the slab, but the mechanism of their formation is not clear, and the castingCasting conditions under which the segregationSegregation is minimized have not been found. In this study, it is reported that a numerical simulationNumerical simulation model for the segregationSegregation have been developed, and the segregationSegregation distribution in the Al–Mg alloy slab was numerically analyzed. As a result, the segregationSegregation similar to that observed in actual slabs was reproduced on numerical analysisNumerical analysis. This simulationSimulation results showed that the channel-type segregationsSegregation could be suppressed by colliding the strong down flow with the solidificationSolidification front.

MicrostructureMicrostructure of DC cast 6000 series Aluminium alloyAluminium alloys billets developed during castingCasting and homogenizationHomogenization largely determine the performance of end product. Apart from chemical composition, castingCasting parameters like castingCasting speed, castingCasting temperature, and cooling water flow rate influence microstructureMicrostructure development during solidificationSolidification. There is a need to understand the effect of each of these variables on the mechanical propertiesMechanical properties of a DC cast Aluminium alloyAluminium alloys billet. In the present investigation, the effects of castingCasting speed, cooling water flow rate, and castingCasting temperature on Yield strength and work hardening behaviour of an AA6063 alloy billet have been discussed. An empirical relationship has been formulated to understand the impact of these operating parameters on mechanical propertiesMechanical properties of the castingCasting.

In this study, aluminium alloysAluminium alloys reinforced by aluminaAlumina (Al2O3) and silicon carbide (SiC) were investigated. Lab-scale DC cast billets with a diameter of 80 mm were cast by ultrasoundUltrasound-assisted stir-castingCasting technology. The billets were subsequently thermo-mechanically processed. The distribution of the particles in the matrix was analysed before and after thermomechanical processingThermomechanical processing. It was found that hot rollingHot rolling improved the distribution of the reinforcement particles in the matrix. Reactions between the reinforcement particles and the matrix were also investigated, and their implications studied. It was found that aluminaAlumina reinforcement reacted with magnesium (Mg) in the alloy to produce spinel and SiC reinforcement oxidised producing a layer of silicon oxide (SiO2) around the particles. The consequences of these reactions are discussed. Whilst theoretical calculations of free energies for different carbides suggested that transition metals in the alloys should substitute the silicon in SiC, no reactions were observed in the physical experimentation. This was attributed to the weight percentages of the transition metals in the alloy being too small. These results are discussed and analysed further in this study, with plans for future experimentation.

An efficient inline melt treatmentMelt treatment process is a key prerequisite for aluminumAluminum producers to ensure compliance with today’s product requirements. Modern DC castingDC casting lines use an equipment chain including Argon degassing, grain refinerGrain refiner addition, and mechanical filtrationFiltration to reduceReduce hydrogenHydrogen and non-metallic inclusionsNon-metallic inclusions to low levels. Individual units of this process chain have been adapted to twin roll casting (TRCTwin roll casting (TRC)) conditions with low meltMelt flow rates, longLong castingCasting campaigns, and high temperature sensitivity, while a holistic concept is pending. Speira and Drache initiated a project to develop a TRCTwin roll casting (TRC) degassing and filtrationFiltration unit based on joint experience combining Argon degassing, CFFCeramic Foam Filters (CFFs) filtrationFiltration and immersion heater temperature management into a user-friendly single box concept with small footprint and high metallurgical performance. This paper describes the technological approach for degassing, filtrationFiltration and electrical heating, the integration into a single-unit concept and initial results of the pilot installation at Speira Karmøy.

The Horizontal Single Belt Casting (HSBC)Horizontal Single Belt Casting (HSBC) process involves castingCasting a thin “river” of molten metal directly onto a fast-moving, continuously cooled, endless belt. By castingCasting at higher cooling rates than is common, uniform solidificationSolidification rates across unconstrained “thin sheets” of meltMelt are maintained, yielding excellent cast properties and microstructuresMicrostructure. A non-isothermal analysis of heat flows in the critical region where the meltMelt first pours onto the water-cooled belt is made and compared with results from an experimental caster. For this, the CFDComputational fluid dynamics (CFD) ANSYS-Fluent 19.1 code was run, using various combinations of meltMelt processingProcessing parameters. It provided accurate predictions of the “windows” available for stable strips of AA6111, AA5182, and AA2024 alloys, to be cast. The HSBC’s significant reductionsReduction in capital and operating costs, due to significantly reduced processingProcessing steps, lower energy consumption, and lower greenhouse gas emissionsGreenhouse gas emissions, make it a valuable alternative to current-day practices.

The main disadvantage of Al–Li alloysAluminum–lithium alloy is their anisotropic behavior and limited formabilityFormability. As conventional processes reach their limits, the formabilityFormability of Al–Li alloysAluminum–lithium alloy is to be improved using twin-roll castingTwin-roll casting (TRC). Twin-roll castingTwin-roll casting (TRC) is an efficient process for the production of thin stripsThin strip. The characteristic of this process is the combination of solidificationSolidification and plastic deformation in a single unit. In this study, the twin-roll castingTwin-roll casting (TRC) of Al–Li alloyAluminum–lithium alloy using copper shellsCopper shell was represented by a numerical simulationNumerical simulation through a thermofluid model implemented in ANSYS-Fluent. This simulationSimulation-based study investigates the influence of castingCasting speed, castingCasting temperature, strip thickness, and length of strip-forming zone on strip outlet temperature and specific size of deformation zone, thus optimizing the practical manufacturing process. The simulationSimulation determined parameters were used to manufacture strips, and the microstructureMicrostructure was analyzed.

Twin Roll Casting (TRCTwin roll casting (TRC)) technology has significantly higher solidificationSolidification rates compared to conventional castingCasting methods. The surface microstructureMicrostructure of the as-cast sheet produced with TRCTwin roll casting (TRC) typically shows a matrix supersaturated by alloying elements, while it also contains segregationSegregation along the centerline of the as-cast sheet. Surface and edge segregations also can be visible in as-cast materials. SegregationSegregation affects the final material properties in terms of the mechanical propertiesMechanical properties, corrosionCorrosion properties, number of pinholes, and rolling performanceRolling performance. It is extremely important to eliminate or reduceReduce the intensity of the segregationSegregation. In this study, the formation mechanisms and parameters for minimizing centerline segregationSegregation in 8xxx8XXX aluminumAluminum foil alloy cast with steel–steel and copper–copper shellCopper shell pairs are investigated. Both surface and edge segregationsSegregation are also studied. As-cast samples are prepared metallographically and investigated by using light microscope, scanning electron microscope equipped with EDS. Electrical conductivityElectrical conductivity measurementsMeasurement are also performed.

In twin-roll continuous castingContinuous casting (TRCTwin-roll casting (TRC)) and aluminumAluminum cold rollingRolling, the rolls are conventionally roughened by grinding. However, this method may cause defects on the surface of the final sheet product. Structures called “shingles” are formed due to the nature of the TRCTwin-roll casting (TRC) method. Because of the shingles, aluminumAluminum debris (SMUT) is carried on to the sheet surface during the manufacturing processes. With sandblastingSandblasting, the surfaces of the rollers are roughened in a different topography, unlike the mill finish textureTextures. Thanks to this topography, the shingle formation mechanism is prevented. With the EDTElectrical discharge texturing (EDT) process applied to the surface of the cold rollingRolling rolls, the resulting crater-like topography helps to eliminate the defective shingle structure from the castingCasting. In this study, sandblastingSandblasting of castingCasting rolls; on the other hand, EDTElectrical discharge texturing (EDT) process was applied to cold rollingRolling rolls. The obtained results were evaluated by using surface characterizationCharacterization methods.

Aluminium alloysAluminium alloys are widely used in many application areas due to the properties of high thermal conductivityConductivity, good formabilityFormability, high corrosionCorrosion resistance, and recyclability. Growing demand for aluminiumAluminium materials leads the aluminiumAluminium manufacturer to increase the castingCasting productivity. One of the effective way to increase the castingCasting speed in twin-roll casting (TRCTwin-roll casting (TRC)) is changing the cooling conditions required for solidificationSolidification. The shell component of a cast roll contacts with the molten metalMolten metal ensures solidification by removing the heat from molten metal. Depending on the thermal conductivityConductivity of shell material, castingCasting speed and productivity can be increased. However, castingCasting microstructureMicrostructure and other properties of the material can change because of the solidificationSolidification conditions. In this study, 8006 alloy is casted by TRCTwin-roll casting (TRC) method using copperCopper–copperCopper roll pairs as an alternative to conventional steel–steel pairs. Microstructural analysis, electrical conductivityElectrical conductivity measurementsMeasurement and mechanical propertiesMechanical properties were investigated comparing with steel–steel casted material.

Extracting the heat from the liquid metal with the help of the water-cooled caster rolls (designed with core and shrink-fitted shell) and then reaching as-cast strip in various thicknesses with different castingCasting speeds generate the phenomena of the twin-roll castingTwin-roll casting (TRC) (TRC) processTwin-roll casting (TRC). In order to increase productivity (combination of the castingCasting speed and as-cast strip thickness) which is one of the most important outputs of the TRCTwin-roll casting (TRC), different shell materials having different heat transferHeat transfer coefficient rate could be used. In case of using St/Cu (steel–copperCopper) shell pair, higher productivity rate could be obtained. However, as-cast microstructureMicrostructure of the materials could have some differences such as behavior of the centerline segregationSegregation and grain structureGrain structure compared to the sample produced by St/St (steel–steel) shell pair. In this study, castingCasting parameters (setback, roll speed, strip speed, and thickness) are changed in order to observe the differences such as centerline segregationSegregation and grain structureGrain structure close to the surfaces.

The vast majority of casthousesCasthouse built in our industry over the past decade were designed with production, not safetySafety, in mind. This issue contributes to many incidents resulting in workers being injured and killed. This paper will discuss the common designDesign mistakes that occur in casthouseCasthouse designDesign and construction. My paper will cover common hazards overlooked during casthouse designDesign. The current designDesign of casthouses focuses on a myriad of other goals excluding safetySafety. I argue that only by focusing first on safety during the designDesign of a casthouse can our industry stop these incidents from injuring and killing workers.

The interference-free functioning of cast houseCast house equipment such as moulds, starter blocksStarter blocks, metal level sensors, or simply the vehicle fleet is critical to a smooth and safe operationOperations. Malfunctions can cause unforeseeable cast stops leading from downtime to safetySafety issues and equipment damage due to bleed-outs, hang-ups, or metal freezing in the nozzles and they certainly reduceReduce productivity. However, the wide variety of equipment used challengesChallenges production and maintenance employees responsible to keep an overview of the usage and condition of each single device at any point in time. Therefore, digital assistant systems seem to be a suitable way to support operationsOperations by tracking such devices on the shopfloor and predict at best equipment conditions depending on the past and future production program. This paper deals with a selection of digital support tools developed and used at AMAG castingAMAG casting to further improve condition-based maintenance and increased equipment availability.

Counter-gravity castingCasting can improve the structural integrity of castingsCasting by eliminating defects resulting from the turbulent flow of the molten metal during filling. The Constrained Rapid Induction MeltingInduction melting Single Shot Up-castingCasting (CRIMSON) is an alternative counter-gravity castingCasting approach designed for improving energy efficiencyEfficiency in castingsCasting in line with the concept of sustainable foundry. In this work, the microstructureMicrostructure and properties of the hypoeutectic 354 Al alloyAl alloy produced by CRIMSON counter-gravity castingCasting is investigated and compared with specimens produced by conventional gravity sand castingCasting in the as-cast condition. The results indicate significant reductionReduction in porosity, oxide inclusionsInclusions and bifilms for the CRIMSON counter-gravity cast samples compared to that in conventional gravity cast samples in line with the controlled liquid flow of the counter-gravity filling. This can lead to significant improvementsImprovement in terms of the castingCasting yield, the expected fatigue resistance of the alloys as well as efficiencyEfficiency of the castingCasting processes in terms of energy, materials use and greenhouse emissionsEmissions. Furthermore, similar dendritic microstructureMicrostructure consisting of α-Al dendrites, Al–Si eutecticEutectic and intermetallic compounds in small volume fraction was observed for both CRIMSON and gravity cast samples. The mechanical behaviour was also evaluated using tensile tests and hardness tests.

VacuumVacuum-assisted plaster mould investment castingInvestment casting is one of the best available processes to manufacture ultra-high complexity castingsCasting for the aerospace and defence sectors. In light of the emerging cross-sectoral manufacturing industry digitalisation, process simulationProcess simulation appears as a very important tool to improve castingCasting yield, reduceReduce metallurgical scrap, and reduceReduce lead time to new product introduction. Considering the unique aspects and the level of customisation of the process system, this work will present a Computational Fluid DynamicsComputational Fluid Dynamics (CFD)-based simulationSimulation tool with bespoke settings (that include thermophysical properties). Optimal fill and solidificationSolidification parameters are identified for a representative geometry able to describe a variety of very complex, high-value aluminium alloyAluminium alloys components through an iterative process.

Carbon anodesCarbon anode used in aluminum electrolysisAluminum electrolysis are made of petroleum cokePetroleum coke, coal tar pitch, recycled anodesAnode, and butts. In order to reduceReduce emissionsEmissions of greenhouse gases (GHG), a group of researchers succeeded to replace a part of petroleum cokePetroleum coke with biocoke modified using additivesAdditive. Biocoke is obtained by the pyrolysis of wood chips at a temperature of about 1100 ºC, which is similar to the maximum temperature reached during anodeAnode baking. The focus of this study is the effect of biocoke productionBiocoke production temperature on the anode qualityAnode quality. In this study, biocoke was produced at four different temperatures (600, 750, 950, and 1100 ºC). AnodesAnode were produced without biocoke (standard anodeAnode) as well as with modified and non-modified biocokes. Then the anodesAnode were characterized by measuring their densities, electrical resistivitiesElectrical resistivity, air and CO2 reactivities, and bending strengths. The effect of biocoke productionBiocoke production temperature on anode qualityAnode quality was determined by comparing the anode propertiesAnode properties.

Worldwide, the quality of petroleum cokePetroleum coke, used for making carbon anodeCarbon anode for aluminium smeltersAluminium smelter, is getting degraded with an increase in the impurities and higher presence of shot coke particles. Earlier studies reported that some of the anodeAnode problemsProblems like slabbing and vertical cracking are linked to the thermal shock resistance of coke material, which is majorly influenced by the structure of calcined petroleum coke (CPCCalcined Petroleum Coke (CPC)). Therefore, a detailed method of optical microscopic analysis was establishedEstablished and successfully applied to evaluate CPCCalcined Petroleum Coke (CPC) materials. The analysis of most of the samples was found to have the presence of sponge and isotropic structure. The findings of the optical microscopy have been correlated with the visual identification of shot, sponge and needle coke. The visual identification of different coke particles enables its integration with digital image processingDigital image processing techniques for ease of quantification of specific coke material.

The bulk densityBulk density of anodeAnode grade petroleum cokePetroleum coke is an important property for aluminum smeltingAluminum smelting and has been extensively studied. This includes previous work by BP showing that particle shapeParticle shape was modified by different crushing technologiesCrushing technology, and that changes in shape (i.e. sphericity and convexity) influenced coke bulk densityBulk density. These laboratory studies indicated that the impact of particle shapeParticle shape on the Vibrated Bulk Density (VBD) of a range of cokes and butts was of similar magnitude to that of porosity. In ongoing customer support efforts, this work has been extended to study whether modifying particle shapeParticle shape can improve the VBD of blends of cokes calcined using different technologies—shaft and rotary hearth kilns. The results of this study are presented and the potential to enhance the VBD of shaft/non-shaft calcined coke blends by modifying particle shapeParticle shape with different crusher types determined at a laboratory scale.

Alba (AluminiumAluminium Bahrain) is one of the unique primary Aluminium smeltersAluminium smelter who has its own calciner plant to produce CPCCalcined Petroleum Coke (CPC), by converting different types of GPCGreen Petroleum Coke (GPC) to CPCCalcined Petroleum Coke (CPC). The quality of GPCGreen Petroleum Coke (GPC) has strong influence on the properties of the anodesAnode. Due to market variations and price fluctuation, the properties of GPCGreen Petroleum Coke (GPC) purchased vary depending on the source. In addition, with latest expansion of Alba being the largest smelters outside China, hence, CPCCalcined Petroleum Coke (CPC) requirements increased accordingly. Such changes bring up great challengesChallenges to both Calciner and Carbon operationOperations team to manage these variations through precise blendingBlending and tuning process parametersProcess parameters to achieve optimum anodesAnode quality. This paper discusses Alba strategyStrategy on managing the variations of GPCGreen Petroleum Coke (GPC) properties along with purchased CPCCalcined Petroleum Coke (CPC) on quality of anodesAnode in terms of desulphurizationDesulphurization, anodeAnode density, baking levelBaking level, stack emissionsEmissions and others anode propertiesAnode properties.

The lifetime of an anodic pinPin in aluminumAluminum production process with Söderberg technology is around 3 years. The main consumption factor of the anodic pinPin is the corrosionCorrosion of the steel by sulphide. To find a protective coatingCoating that will withstand the cycles of use and cleaning of anodeAnode pinsPin is the main problemProblems. The objective of this study was to investigate the formation and application of IronIron Aluminide, due to its high resistance to sulphidationSulphidation, as a coatingCoating for anodic pinsPin. The application method chosen was the deposition of the mixture of aluminumAluminum and ironIron powders using laserLaser cladding. Results showed the formation of ironIron aluminide, either in the form of FeAl or Fe3Al during application, which makes this material promising for this purpose.

New measurementMeasurement techniques aiming to achieve a better understanding of the PAHPolycyclic Aromatic Hydrocarbons (PAH) emissionsEmissions dynamics during production of electrode paste briquettes were tested. Traditional sampling method requires several hours of sampling to get enough PAHPolycyclic Aromatic Hydrocarbons (PAH) components on the adsorbent material to perform reliable analysis. As the process is changing from one batch to the next, emissionsEmissions cannot be expected to be constant over time. Better time resolution is essential to increase the understanding of emissionEmissions variations. Thermal desorption (TD) tubes allow for sampling times as short as 10 min. The SINTSENSE, a standalone photo ionization detector (PID) implementation allows for continuous emissionEmissions monitoring providing online data second by second. However, the SINTSENSE will only report a total hydrocarbon estimate, with no differentiation between individual components. Comparing results from these 3 methodologies gives interesting findings on the emissionEmissions dynamics and variations in composition, in addition to benchmarking the individual measurementMeasurement techniques.

Producing anodesAnode with the highest uniformity and consistent properties is essential to improve the energy efficiencyEfficiency and productivity of the Hall-HéroultHall-Héroult process. Achieving this objective is a great challengeChallenges, as it requires advanced investigations of all parameters related to process and materials which may influence the quality of the anodeAnode. Stacking anodesAnode at the baking stage may be another parameter influencing their final properties. During the baking process, the anodesAnode are stacked in the pits of the furnace and baked according to predefined temperature profiles. Stacking the anodesAnode may generate mechanical stressMechanical stress on the lower anodesAnode. This additional stress state could affect the rearrangement of the anodeAnode coke particles, leading to internal structure anisotropyAnisotropy. To investigate the effect of this parameter, we measured the electrical resistivityElectrical resistivity and density of the anodesAnode baked at different positions in the furnace. The results show a statistically meaningful variation of the electrical resistivityElectrical resistivity as a function of anodeAnode position in the rows of the furnace.

The anodesAnode used for aluminiumAluminium production are baked in order to reach the resistivity, mechanical resistance and reactivity adequate for the electrolysisElectrolysis process. The anodesAnode are baked in pits that are usually separated from each other by fluewalls and headwalls made of dense refractory material. In 2017, an industrial prototype of the new generation anodeAnode baking technology was installed at the Bell-Bay smelter with 6 sections converted to this patented technology. The headwalls were partially removed to allow a productivity increase by 17% and gas consumption reductionReduction by 30%. After the success of this first trial, the conversion of five additional 6-sections zones by the end of 2025 is planned for Bell-Bay’s furnace. The use of prefabricationPrefabrication has been developed and implemented for the installation of the second generation of walls to: 1. shorten the construction duration and limit the production loss, 2. improve the ergonomics and safetySafety for the construction workers and, 3. improve the overall brick assembly quality. This paper reviews the process that led to an optimized second NG zone construction through prefabricationPrefabrication.

The new AHEX technology for treating the off gas fumes from the anode bakingAnodes baking furnaces has been successfully demonstrated since 2018 for a complete new FTC at TRIMET Hamburg. With this new technology, the fumes are cooled in an indirect heat exchanger with water in a closed loop. Thereby, many issues with corrosionCorrosion and deposits inside the traditional FTC based on the conditioning tower designsDesign are avoided. AluminaAlumina is injected into the AHEXAHEX to keep the surfaces clean, and at the same time the aluminaAlumina absorbs and removes part of the undesired components from the off gas stream. The less sticky and less humid gas due to the AHEX improves the operationOperations conditions for the filter bags. The paper will present performance results achieved including operational and maintenance experiences over time after the start up of the first full scale AHEX FTC installed at TRIMET’s Hamburg anode bakeAnode Bake furnace.

An anodeAnode and cathodeCathode quality system based on modal analysisModal analysis has been developed. The modal detection system finds the resonances, or “fingerprint”, of the item tested by measuring the movements of the item caused by an input force from a hammer or shaker. The modal method is verified by modeling and measurementsMeasurement of anodesAnode and cathodesCathode to extract crack information and the elastic property, Young’s Modulus ( $${\varvec{Y}}{\varvec{M}}$$ Y M ). MeasurementMeasurement times around $$60\,\boldsymbol{ }{\varvec{s}}/{\varvec{i}}{\varvec{t}}{\varvec{e}}{\varvec{m}}$$ 60 s / i t e m can be achieved. For a modal inline quality station to measure $${\varvec{Y}}{\varvec{M}}$$ Y M , the dimensions and weight of the item must be measured in advance. The resonances need also to be identified by mode shapes. Mode shapes are also important when it comes to extracting the crack plane orientation. The method has a significant potential of detecting anodeAnode and cathode cracksCathode crack that can cause metal infiltration, unstable cell operationOperations, poor cell performance, extra handling and early cathodeCathode failures. In addition, the modal test can provide feedback to production plants of anodesAnode and cathodesCathode to produce those items that are closest to the reference spectrum of resonances of a crack free homogenous product.

ScandiumScandium is a critical metalCritical metal with increasing demand in modern technologies, like solid oxide fuel cells and light-weight Al-Sc alloys. Sc is present at considerably high concentrations in various metallurgical by-products, including the bauxite residueBauxite residue (BR). ScandiumScandium extraction from the Greek bauxite residueBauxite residue (BR) that contains 70–100 mg/kg Sc has been demonstrated at an industrial pilot plant at MYTILINEOS. BR has been treated with sulfuric acid at conditions that allow for low acid consumption. In such conditions, high Sc leaching selectivity is achieved over Fe and Ti, which are the main impurities for the further purification of the leachate through the ion-exchange technique. This paper reports on the recent investigations on the effect of pH control during the leaching process, which can lead to optimized results. Moreover, the treatment of the produced leachate solution is also studied, in order to further refine it, prior to the ion-exchange.

ScandiumScandium is present in titaniumTitanium dioxide feedstock (ilmenite, titania slags, etc.) and usually reports to process solutions and effluents either at the feedstock producer site or at the end user site (TiO2 pigment or Ti metal plant). In this paper, we report on the refining of scandiumScandium from such solutions by solvent extractionSolvent extraction. A mixture of D2EHPAD2EHPA and TBP was used to extract scandiumScandium from a scandium-rich intermediate aqueous solution, which had been previously recovered from a titania slag upgrading process. ScandiumScandium loaded organic was scrubbed with H2SO4 to remove titaniumTitanium and thorium, and the scrubbed organic was stripped with NaOH to produce an impure scandiumScandium hydroxide precipitate. The precipitate was dissolved in H2SO4, and the resulting solution was treated further with Alamine® 336 and Aliquat® 336 to remove persistent impurities. The formation of solids in the D2EHPAD2EHPA stripping step was a significant process issue, but ultimately high purityPurity scandiumScandium oxide was produced. For reasons not related to the work reported here, Rio Tinto eventually selected other processingProcessing methods for its scandiumScandium extraction plant in Sorel-Tracy, QC, Canada.

AluminumAluminum-based alloys containing minimal amount of scandiumScandium have been extensively investigated for their exceptional mechanical propertiesMechanical properties which make them particularly suitable for advanced engineering applications such as aerospace and defense by allowing designDesign and construction of high-strength, lightweight structural parts. Understanding the challengesChallenges in scandiumScandium sourcing, recoveryRecovery and purification processes, and alloying methods, a vertically integrated solution has been developed which includes a portfolio of technologies: (i) patented recoveryRecovery of Sc from Sc-containing ores and industrial waste streams from ppm levels to 20–25% in the concentrate—validated in the pilot scale; (ii) purification of Sc from concentrates containing impurities such as titaniumTitanium, ironIron and other rare earths to produce >99.5% pure scandiumScandium oxide—validated in the commercial scale; and (iii) patent-pending technology for production of the final alloy through a one-step alloying process using a vacuumVacuum induction furnace, refined castingCasting technique, and suitable heat treatmentHeat treatment processes—validated at demonstration scale.

The production of AluminumAluminum ScandiumScandium (AlScAlSc) master alloyMaster alloy ranging between 2 and 8wt % is of interest because this alloy family has outstanding material properties, such as strength-to-weight ratio, weldability and corrosionCorrosion resistance. Despite its attractive properties, commercialization of ScandiumScandium-containing aluminum alloysAluminum alloys has been hindered by the lack of availability and high cost of ScandiumScandium (Sc). This has resulted in very little development in this space. However, access to this material is projected to increase in the coming years. The increase in supply will lower the cost of Sc, enabling commercialization of AlScAlSc, as longLong as low-cost productionLow-cost production techniques are also available. FEA Materials LLC (FEAM) has developed a hybrid metallothermicMetallothermic/electrolysisElectrolysis process (FEAM Process) that enables production of Al-2%Sc below $40/kg at scandiumScandium oxide market price of $1000/kg or lower. The FEAM Process can theoretically achieve Sc concentrations as high as 8wt % in the alloy, with consistent concentrations of up to 4wt % observed in experiments to-date. The system is designed for continuous operationOperations and maintains a material yield above 90%. The FEAM Process uses a proprietary molten saltMolten salt composition that is both robust and self-correctingSelf-correcting, overcoming the challengesChallenges with traditional electrolysisElectrolysis processes. The cell platform is modularModular platform, allowing for tuned production rates and flexible infrastructure requirements. The FEAM Process runs under a controlled atmosphere to keep tight control of output streams and to ensure a safe work environmentEnvironment (no perfluorocarbonPerfluorocarbon (PFC) emissionsEmissions). FEAM is currently producing upwards of 16 kg Al 2%Sc per shift with the capability to expand to 50 kg/shift within its facility in Westborough, Massachusetts.

ScandiumScandium is a critical component for high strength aluminumAluminum products, yet manufacture is burdened by challengesChallenges in metal reductionReduction and alloying. Current best practice begins with generation of an aluminumAluminum-scandiumScandium master alloyMaster alloy from oxide or halide precursors. However, this approach is characterized by high costs and large environmental impacts. Recent results have shown that employing a metal sulfide feedstock for aluminumAluminum master alloyMaster alloy production increases metal yieldMetal yield and improves process economics. Herein, we conduct the sulfidationSulfidation of scandiumScandium oxide using elemental sulfur to generate a scandiumScandium sulfide intermediate, which we experimentally confirm to be amenable for reductionReduction to metal. We demonstrate production of aluminumAluminum-scandiumScandium master alloyMaster alloy at the hundred-gram scale from scandiumScandium sulfide using aluminothermic reductionAluminothermic reduction via reactive vacuumVacuum distillation. Chemical analysisChemical analysis is conducted to determine product purityPurity and yield. Operating conditions to manufacture master alloysMaster alloy with scandiumScandium contents of 2 wt% and higher are tested.

ScandiumScandium is a soft silvery metal, with an atomic number of 21 it is the lightest of the transition metals. The melting pointMelting point is 1.541 °C, the boiling pointBoiling point is 2.836 °C and with a density of 2.985 g/cm3 is slightly heavier than AluminiumAluminium. ScandiumScandium is actually not rare—it is more abundant than precious metals and commercial metals like cobalt, lead and mercury. ScandiumScandium is primarily produced as a byproduct from the mining of other metals or minerals like BauxiteBauxite, Coal, Rare Earth Elements (REE), IronIron, Tungsten, Uranium, Zirconia or Titaniumdioxide. ScandiumScandium and scandiumScandium compounds have unique properties for many advanced technological applications. ScandiumScandium is considered as a Strategic metal by the EU and by the US government due to the current limited Western supply situation. ScandiumScandium is increasingly used in energy storage systems such as solid oxygen fuel cells (SOFC) and for green hydrogenHydrogen production in solid oxide electrolyser cells (SOEC). AlScN piezoelectric films for energy generation are important compounds for 5G applications. Today, the EU imports 100%, mainly from China. Therefore, a continuous supply of scandiumScandium at reasonable prices must be ensured in and for Europe, and the dependency on China must be reduced. Europe is leading in the development of green technologies and has sufficient scandiumScandium resources. This paper will briefly explain the status and potential of ScandiumScandium compound production in Europe, in particular providing an update on the ScaVanger project.

The exceptional strengtheningStrengthening potential of scandiumScandium additions to aluminumAluminum was first discovered in the 1960s. The impact that scandiumScandium additions have on the alloys’ properties varies with parameters of the thermo-mechanical process and alloy composition. The benefits from scandiumScandium come from the various influences it has on the alloys’ microstructureMicrostructure which can be summarized as four main effects, grain refinementGrain refinement, increased recrystallisation temperature, dispersoidDispersoids strengthening and nucleation of strengthening phase. The strength improvementImprovement from Sc additions is mainly provided by the formation of fine dispersions of Al3Sc L12 dispersoidsDispersoids. The level of strengthening depends on the size and number density of these dispersoidsDispersoids. Temperatures in the range of 250 to 350 °C are usually preferred to nucleate a high number of small Al3ScAl3Sc. The use of higher temperatures will most commonly generate coarser particles with less strengtheningStrengthening potential. This paper reviews the heat treatmentHeat treatment strategiesStrategy to generate fine dispersions of dispersoidsDispersoids, the origins of dispersoidDispersoids strengtheningStrengthening, the impact of strengtheningStrengthening in different alloy series and finally the effect of adding Sc in combination with Zr.

The properties of 5xxx5xxx aluminum alloysAluminum alloys can be improved with small additions of Sc. When Sc and Zr are added to 5xxx alloys, the alloys become heat-treatable as Al3(Sc,Zr) nanoprecipitates form at 300–400 °C. However, the heat treatmentHeat treatment and thermo-mechanical processingProcessing (TMP) need to be adapted to maximize the value of the Sc addition. In this work, AA5083 slabs were DC cast with and without minor additions of Sc and/or Zr. The room/elevated temperature mechanical propertiesMechanical properties of the cast materials were evaluated after various annealingAnnealing and homogenizationHomogenization treatments. Samples were then hot and cold rolled with different TMP treatments. The microstructureMicrostructure, room temperature mechanical propertiesMechanical properties and corrosionCorrosion performance were evaluated for selected tempers. It was evident that the properties could be improved significantly with small additions of Sc, but that this depends very much on the amount of Sc and on the processingProcessing parameters.

The use of aluminumAluminum makes it possible to reduceReduce the weight of the car, thereby improving the environmental impact of transport by reducing CO2 emissionsEmissions. RollingRolling sheets made of 5182 alloy are widely used for the manufacture of BIWBIW parts using deep drawingDeep drawing. However, to increase the weight efficiencyEfficiency of the car it is necessary to develop an alloy with higher mechanical propertiesMechanical properties without losing processability. The results of previous studies of 5XXX5xxx series alloys showed that additivesAdditive of ScandiumScandium, ZirconiumZirconium and other REERare-earth element (rare earth elementsRare-earth element) and TM (transition metals) lead to a significant increase in strength characteristics. The work presents the results of studies of the influence of small additives of Scandium and other REEInfluence of small additives of Scandium and other REE on the mechanical and technological properties of alloys based on 5182, as well as the dependencies of changes in the level of mechanical and technological properties on rollingRolling and heat treatmentHeat treatment parameters are establishedEstablished.

5xxx5xxx aluminum alloysAluminum alloys are traditionally considered non-heat-treatable. With the addition of Sc/Zr and multistep heat treatmentHeat treatment, two kinds of dispersoidsDispersoids (AlMn and Al3(Sc,Zr)) were formed. The effect of Sc additions (0.08–0.43 wt.%) on dispersoidDispersoids formation and mechanical propertiesMechanical properties of hot-rolled sheets was investigated. The results showed that tensile properties initially increased with increasing Sc addition. The yield strength (YS) and ultimate tensile strengthTensile strength (UTS) of the alloy with 0.16 wt.% Sc reached 295 and 411 MPa, respectively, showing improvementsImprovement of 28% in YS and 8% in UTS compared to the base alloy. However, with a further increase of Sc, the tensile properties declined owing to the formation of a line/fan-shaped microstructureMicrostructure associated with discontinuous Al3(Sc,Zr) precipitationPrecipitation during solidificationSolidification. The evolution of Al3(Sc,Zr) and AlMn dispersoidsDispersoids during heat treatmentHeat treatment and hot rollingHot rolling was characterized using scanning and transmissionTransmission electron microscopies. Their influence on the mechanical propertiesMechanical properties of hot-rolled AA5083 alloys was discussed.

AluminumAluminum-copperCopper-scandiumScandium alloys show significant potential for high-strength applications; however, the formation of the detrimental W-phase (nominally Al8Cu4ScAl8Cu4Sc) has prevented commercial adoption. There is not a strong consensus as to what conditions lead to the formation of W-phase, but two key factors are the cooling rate during solidificationSolidification and the homogenizationHomogenization heat treatmentHeat treatment. In this work, the effect of cooling rate on the formation of W-phase in Al-Cu-Sc alloysAl-Cu-Sc alloy is investigated utilizing wedge molds that produce solidificationSolidification rates from ~0.25 to 100 K/s. Samples are examined in both the as-cast state and following homogenizationHomogenization and agingAging treatments.

Solute clusteringSolute clustering during natural ageingNatural ageing in Al-4wt.%Cu alloys with and without Sc and Zr has been studied. The alloys were heat treated to form Al3(Sc, Zr) dispersoidsAl3(Sc, Zr) dispersoids before being solutionised at 500 °C followed by a water quench. Scanning transmissionTransmission electron microscopy (STEM) and atom probe tomography (APT) were used to characterize Al3(Sc, Zr) dispersoidsAl3(Sc, Zr) dispersoids in the Sc- and Zr-containing alloy. The APT results show that Cu segregates at the interfaces between Al3(Sc, Zr) dispersoidsAl3(Sc, Zr) dispersoids and the Al matrix. Solute clusteringSolute clustering during natural ageingNatural ageing was quantified in situ with small-angle X-ray scattering (SAXS). The in situ SAXS results show that the presence of Al3(Sc, Zr) dispersoidsAl3(Sc, Zr) dispersoids significantly retards the solute clusteringSolute clustering formation during natural ageing in the Al-Cu alloysAl-Cu alloys. This could be related to the Cu segregationSegregation at the Al3(Sc, Zr) dispersoidsAl3(Sc, Zr) dispersoids/Al matrix interfaces, which could deplete the solid solution from Cu solute which is no more available for solute clusteringSolute clustering. Additionally, Sc solutes could bind with vacancies which reducesReduce the free vacancies for the diffusion of Cu.

We studied the effect of zirconiumZirconium and scandiumScandium on an Al-7 wt% Fe cast alloyCast alloys with potential heat- and wearWear-resistant applications. An addition of 0.2% Zr resulted in thinning of primary Al3Fe particles, while an addition of 0.15% Zr and 0.15% Sc changed the morphology of primary intermetallics from needles to flower-like shape. While the addition of Zr did not affect the properties, the Zr + Sc joint additions increased the hardness of the as-cast Al–Fe alloyAl–Fe alloy. The hardness of the base alloy increased upon annealingAnnealing from 40 to 80 HV (450 °C, 2 h) and to 110 HV (350 °C, 20 h). The wearWear resistance of the Al–Fe alloyAl–Fe alloy was also improved by Zr and Sc addition, especially after annealingAnnealing. The observed effects are likely to be linked to the supersaturation of Zr and Sc in the aluminumAluminum solid solution during solidificationSolidification and precipitationPrecipitation of dispersoidsDispersoids during annealingAnnealing.

The modern trend of transport is electric vehiclesElectric vehicle. This is due to the high environmental friendliness of electric vehiclesElectric vehicle and international regulations that regulate carbon footprintCarbon footprint. Aluminum alloysAluminum alloys are good alternative to copperCopper for use in bus bars and wires. In order to replace copperCopper for the manufacture of bus bars for electric vehiclesElectric vehicle, aluminum alloysAluminum alloys should have high electrical conductivityElectrical conductivity at the level of technical grades (AA 1350) and at the same time have increased strength and thermal stabilityThermal stability. The most promising method of improving strength properties is doping with small additivesAdditive Sc, Zr, and REERare-earth element, which form fine dispersed precipitates, providing an increase in strength properties, significantly increasing recrystallizationRecrystallization temperature and thermal stabilityThermal stability. In the present paper, a study of the effect of additivesAdditive of a small amount of Sc, Zr, and other REERare-earth element on mechanical propertiesMechanical properties and electrical conductivityElectrical conductivity alloys of aluminumAluminum of 1XXX series was carried out.

The effect of a minor Sc addition (within 0.1 wt.%) to improve the mechanical propertiesMechanical properties and electrical conductivityElectrical conductivity of Al-Zr-Sc conductor wires was investigated. The thermal-resistance propertiesThermal-resistance properties of Sc-containing wires after thermal exposure at 310 °C and 400 °C were evaluated according to the international standard IEC 62,004. The results show that a simultaneous improvementImprovement of mechanical propertiesMechanical properties and electrical conductivityElectrical conductivity while maintaining outstanding thermal resistance was achieved by microalloying with Sc in comparison with the base Al-Zr alloy. This was attributed to the precipitationPrecipitation of a high number density of Al3(Sc, Zr) nanoparticles. Excellent combination of ultimate tensile strengthTensile strength and electrical conductivityElectrical conductivity (188–197 MPa and 58.0–59.5% IACS) was obtained in Sc-containing alloys using conventional thermomechanical process (e.g., castingCasting, rollingRolling and wire drawing) to fulfill the particular requirements of different standard conductor grades. The newly developed conductor alloys provide a much-needed outstanding performance for overhead line applications in the electric industry.

The laserLaser-powder bed fusion (L-PBF) processingProcessing environmentEnvironment poses significant challengesChallenges for the expansion of materials available for usage as a result of the drastic cooling rates native to this manufacturing method. First introduced in the castingCasting manufacturing ecosystem, the incorporation of small amounts of grain refining rare-earth metals, particularly scandiumScandium, into aluminum alloysAluminum alloys (Al alloysAl alloy) provided an avenue to resist the detrimental effects imposed by extreme thermal gradients, while also imparting a not insignificant increase in material strength. Through the analysis of solidificationSolidification behaviour, complementary element pairings, and owing to the supersaturation potential in these manufacturing conditions, a material designDesign strategyStrategy is outlined based upon observations made through experimentation and from the literature. Results show that an apparent extensive processingProcessing window exists for the material studied, with many opportunities for further improvementImprovement of print results available. Further work objectives are outlined for work involving the synthesis of new materials using scandiumScandium as a significant additiveAdditive, owing to its grain refining qualities.

With the upcoming limitations on gasoline-based vehicles, especially in Europe under the Paris Accord, research on electrical/hydrogenHydrogen powered vehicles and lightweight alloys for lower CO2 emissionEmissions has peaked. ScandiumScandium (Sc) became one of the key elements for advanced Al-based lightweight alloys due to major improvementsImprovement in physical properties. Due to extreme prices and rare primary sources, recoveryRecovery of Sc from available end-of-life (EoL) products has clearly became the focus of research. Al-Sc-containing 3D printing powders are one of the promising products to be utilized in the industry. To recover the critical metalsCritical metal from these EoL products or from the production wastes, hydrometallurgical processes are great alternatives due to possibility of elemental separationSeparation with low energy consumption. However, conventional leaching of electronegative metallic particles and alloys with a strong mineral acid can result in generation of H2 gas and an aggressive exothermic reaction. While such a leaching process can be made safe at laboratory scale there are significant challengesChallenges at commercial scale from a control and zero harm perspective. Hence, there is a need for greener and sustainable process with easier control, lower chemical use, energy, and CO2 emissionEmissions without any H2 gas evolution. Thus, an innovative leaching approach was applied with a metal salt solution with higher reductionReduction potential to dissolve the metallic powders with cementation of the metal from the leaching solution. Then, the target was separated and purified from the impurities via refining operationsOperations. The flexibility of end product is another advantage since metal carbonates, metal sulfatesSulfates, metal oxides, metal fluoridesFluoride and metal oxides could be produced via this processingProcessing route. The process is also scaled up and tested in a continuous mini-pilot scale.

This work explores new weldingWelding wire compositions tailored for the emerging technology of Wire Additive ManufacturingAdditive manufacturing (WAM). The 5183 alloy is a commonly used weldingWelding wire as it provides strength through the presence of a high content of Mg through solid solution strengtheningStrengthening mechanism. These alloys experience a number of shortcomings such as low strength compared to age-hardenable alloys and are prone to sensitisation when used in marine environmentEnvironment. This work uses co-additions of Sc, Zr, and other transition elements to a 5xxx5xxx-series alloy to provide additional strengtheningStrengthening through the formation of L12 Al3X particles. The formation of the Al3X during a tailored heat treatmentHeat treatment will be discussed. Tensile tests are conducted to evaluate the impact on the mechanical propertiesMechanical properties. Atom probe tomography and transmissionTransmission electron microscopy are used to better explain the role of the different elements on the formation kinetics of Al3X. The newly developed alloys will enable the creation of high strength, corrosionCorrosion resistant WAM structures.

In this work, Al-5 Mg-0.1Ti and Al-5 Mg-0.1Ti-0.2Sc-0.1Zr (wt.%) alloys fabricated by cold metal transferCold metal transfer (CMT) and electron beam additive manufacturingElectron beam additive manufacturing (EBAM) are investigated. The Sc and Zr additionSc and Zr addition improves the processability of Al–Mg-Ti alloys by eliminating cracks in their as-deposited microstructureMicrostructure. Additionally, the Sc and Zr additionSc and Zr addition promotes columnar to equiaxed transition in the as-deposited Al–Mg-Ti alloys, exhibiting a fully equiaxed microstructureMicrostructure with grain sizes decreased by at least 70% compared to the unmodified alloys in both cases. Grain refinementGrain refinement in the as-deposited Al–Mg-Ti-Sc-Zr alloy samples is attributable to the inoculation effect of primary Al3(Sc, Zr, Ti) phase and Zener pinning effect of the solid-state precipitates of Al3ScAl3Sc. Moreover, the Sc and Zr additionSc and Zr addition improves the hardness of Al–Mg-Ti alloys in the as-deposited state, achieved by grain size strengtheningStrengthening and precipitate strengtheningStrengthening.

Aluminum alloysAluminum alloys are of growing interest in fields requiring lightweight structural materials and are common in additive manufacturingAdditive manufacturing applications. AluminumAluminum wire-arc additive manufacturingAdditive manufacturing (WAAMWAAM) as a method of production is also increasing in development and use, predominantly using available weldingWelding filler alloys (i.e. 5356, 5183, etc.) as feedstock. As a manufacturing method, there is an interest in pursuing new aluminum alloyAluminum alloys development to produce superior strengths to currently available materials. Alloys of aluminumAluminum and scandiumScandium offer increased strength as well as post-processingProcessing heat treatability that makes them well suited as a feedstock for WAAM applications, however, the complex thermo-mechanical history of wire production, as well as the thermal input during WAAM processingProcessing, has a significant impact on the precipitationPrecipitation, dissolutionDissolution, structure, and morphology of Al3ScAl3Sc dispersoidsDispersoids. In this work, aluminum alloyAluminum alloys 5025 is used to produce WAAM structures, and the resulting material properties and characteristics are analyzed. TransmissionTransmission electron microscopy is used to study Sc dissolutionDissolution, Al3X dispersoidDispersoids morphology, and dispersoidDispersoids chemistry in WAAM samples in both the feedstock and as-printed conditions. Suggestions are made for optimizing Al-Sc alloys in WAAMWAAM applications.