TMS 2021 150th Annual Meeting & Exhibition Supplemental Proceedings

In recent years, it has been found that lowering the dimensionality of halide perovskites leads to enhanced photoluminescence and stability than their three-dimensional counterparts. Further, the change in the dimensionality of an inorganic halide perovskite can evoke surprising ramifications to its intrinsic behavior. The dimensionality in perovskites is governed by its octahedral cages. In zero-dimensional perovskites, the octahedral cages are discrete, whereas in two-dimensional perovskites, they are connected with one another resulting in the formation of a layer. Likewise, in three-dimensional perovskites, the octahedral cages share the corner atoms with each other. This study describes the two-dimensional counterpart of cesium lead bromide perovskites. The structuralStructural properties, electronicElectronic properties and optical propertiesOptical properties, in conjunction with their three-dimensional structure, are presented. The emergence of new physical phenomena with respect to the decreasing dimensionality of cesium lead bromide perovskites is analyzed.

Coal gasification fine slag (CGFS) is a kind of industrial waste with more than 30% of carbon, a large surface area, and a broad pore size distribution, which provides favorable conditions for the preparation of activated carbon. In this paper, activated carbon was prepared from residual carbon of CGFS processed by flotation and modified by nitric acid. The effects of nitric acid on the pore structurePore structure, surface properties and electrochemical performanceElectrochemical performance of activated carbon were investigated. The results showed that after treated with nitric acid, the content of mesoporous and surface functional groups of coal-based activated carbonCoal-based activated carbon increased, leading to the significant improvement of electrochemical properties and electro-adsorption performance.

A unique and novel concept about laser printingPrinting technology by incorporating a preformed cartridge was proposed to fabricate two-dimensional (2D) heterostructureHeterostructures photoelectric devices. COMSOL multiphysics software was used to perform a simulationSimulation to study the factors influencing laser printingPrinting performance by constructing a 3D physical model, including material thickness, laser power and spot size. The thinner material thickness can ensure the same temperature distribution on the upper and lower surfaces of PPC, which is conducive to the consistent melting performance. The laser power mainly affects the temperature intensity. The laser power needs to be finely adjusted because even if the laser power differs by 0.5 mW, the temperature can differ by close to 5 °C. The laser spot size has a great influence on the temperature resolution, with the resolution of 100 and 200 nm differing by about 1 time. Under optimal conditions, a resolution of 48 nm can be obtained, which is only nearly 50% of the laser spot size. It is also feasible to obtain 2D materialsTwo-dimensional materials of other sizes by modifying the parameters to achieve a flexible and controllable preparation scheme. In addition, it is achievable to accomplish a multilayer printingPrinting process of 2D materialsTwo-dimensional materials that do not affect each other, thereby realizing the free combination of heterostructuresHeterostructures. The simulationSimulation results provide a foundation for technology optimization of subsequent process realization.

This paper will focus on the research and collective work of Emerging Objects, a MAKE tank, that is transforming materials into sustainable buildings for the future using additive manufacturing. Humble and traditional building materials, such as salt and soil, can be transformed into sophisticated building materials through additive manufacturing. Waste materials such as sawdust and chardonnay grape skins and seeds are converted for use in 3D printing3D printing and turned into bricks, blocks, and tiles for construction assemblies. The use of additive manufacturingAdditive manufacturing technologies and radical, alternative materials, will allow architects and engineers to impact the way buildings and cities will be constructed in the future.

In order to decrease the amount of bentoniteBentonite in the production of oxidized pelletsOxidized pellets, the addition of HS binder is carried out in response to the problems of wasting of resources, high costing and serious pollution in the production and application of bentonite in China. In this study, the effect of the organic binderOrganic binder in iron ore pellets was characterized by using pelletizing, preheating and roasting experiments; the optimal ratio of HS binder to bentonite was determined. The results showed that combination of bentonite and HS binder can significantly reduce the amount of bentonite. When the ratio of bentonite of HS binder was HS binder dosage 0.2% and bentonite dosage 0.7%, the drop strength of green pellets reached 3.2 times/(0.5 m) and the amount of bentonite reduced the mass of 1.6% compared with that of without HS binder. Under the best preheated roasted conditions, the strength of the preheated ball was 436.9 N/P and the roasted ball strength achieved 2794.3 N/P, which could meet the demands.

Linear friction weldingLinear Friction Welding (LFW) (LFW) is a solid-state joining process offering new opportunities of cost reduction and quality improvement for aerospace titaniumTitanium Welding part manufacturing. The process produces in a few seconds high integrity joints with fine grain, hot-forged microstructure and narrow heat-affected zone. The LFWLinear Friction Welding (LFW) process reached a high enough level of maturity, robustness, and reliability to be ready for mass production of blisksBlisk (“bladed disks”) for aircraft engines. It is now being developed for aircraft structural parts in titaniumTitanium Welding and aluminum alloys. This process allows not only to manufacture a given part at a lower cost, it also opens new part design possibilities that were not available with traditional manufacturing processes. The LFWLinear Friction Welding (LFW) process is explained through physical aspects, process parameters, mechanical characterization of the joint, and microstructural data. Several LFWLinear Friction Welding (LFW) aerospace applications are introduced and evaluated through feasibility, weight reduction, post-weld operations, and overall cost savings.

DefectsDefects are inevitable in metal parts manufactured by any process; the size, shape and location of such defectsDefects play a critical role in determining the material’s fatigueFatigue strength. Due to the random nature of the defects’ distribution in the part, a statistical method must be employed for fatigueFatigue strength estimation. The laser powder bed fusionLaser powder bed fusion (L-PBF) process introduces two main types of porosity defectsDefects: keyhole pores and lack-of-fusion pores. A defect-based statistical fatigueFatigue strength model has been developed and validated for the L-PBF AlSi10MgAlSi10Mg aluminum alloy containing keyhole defectsDefects with different size distributions. Artificial defects were also introduced for model validation. The approach is based on the modified Murakami’s formulation to address the material dependence and followed the Romano’s approach to consider the statistical behavior of the fatigueFatigue strength. The proposed model successfully predicts the fatigueFatigue strength of different keyhole porosity distributions but is unable to predict the fatigueFatigue strength of materials containing lack-of-fusion porosity, possibly due to the higher stress concentration induced by its morphology.

Laser remelting is often used during selective laser meltingSelective laser melting (SLM) processes to restrain the residual stressResidual stress and improve the mechanical strength of the products. However, researches regarding its effects on porous metals with trabecular or thin-walled structure are still quite lacking. Hereby, remelting treatments have been employed during the SLM processes of a porous Ti-6Al-4VTi-6Al-4V alloy in this study and their influences on dimensional accuracy, microstructure, mechanical propertyMechanical property, and residual stressResidual stress were researched. The results indicate that remelting treatments can provide a stronger bonding condition for the cellular structure, and improve the yield strength and elastic modulus of the alloy. Rescanning with 75% energy density results in 33.5–38.0% reduction of residual stressResidual stress. In terms of pore structure and morphology, the porosities of remelted specimens are 2–4% lower than that of single-scanned specimens. This inconsistency increases with the increase of sheet thickness. It is suggested that the rescan laser power should be turned down during the preparation of porous titanium with thick cell walls to ensure dimensional accuracy.

Stress gradient influence factors and fatigueFatigue notch factors were measured for the AlSi10MgAlSi10Mg aluminum alloy produced by laser powder bed fusionLaser powder bed fusion (L-PBF) processing with respect to different stress gradients (notch geometries). Modeling the stress gradient is critical for accurate fatigueFatigue life estimations for parts containing notches or fillets. Uniaxial fatigueFatigue tests were performed to obtain the fatigueFatigue strengths at R =  −1 for notched and unotched specimens. The fatigueFatigue results were then used to calibrate the stress gradient influence factor model for fatigue life estimation. Due to the small grain size produced by the L-PBF process, the stress gradient influence factor is much lower compared to the cast A319-T7 alloy (at 120 °C) at the same stress gradient.

Advances in aerospace component manufacturing design are being achieved through the additive manufacturingAdditive manufacturing (AM) technology. Variations in cyclic loads (i.e. variable amplitude fatigueVariable-amplitude fatigue) is a common phenomenon experienced by aerospace components during in-service use, hence the need for AM components to withstand fatigue failure under these conditions. This study has performed progressive strain amplitude fatigue tests at increasing strain ranges with the intent to capture the fatigue failure life, hardening/softening response, and fracture response of as-built direct metal laser sintered (DMLS) Stainless Steel GP1Stainless-steel GP1. Preliminary results indicate fatigue failure in specimens prior to reaching strain ranges where plasticity effects become more pronounced. Also, evident is variation in cyclic softening/hardening response to stabilization at elastic versus plastic strain ranges. Scanning electron microscopy was used to identify the precursors for fatigue crack initiation and propagation under progressive amplitude fatigue loading.

Quality control of additively manufactured (AM) Additive manufacturing (AM) metallic structures is essential prior to deployment of these structures in a nuclear reactor. We investigate the limits of detection of sub-surface porosity defects in AM stainless steel 316L using thermal tomographyThermal tomography nondestructive evaluationNondestructive evaluation method. Thermal tomography reconstructs spatial thermal effusivity of the structure from time-dependent surface temperature measurements of flash thermography. Our studies are based on computer simulations of heat transfer through solids using COMSOL software suit. Using the model of layered media, in which defect in a solid is represented with a layer of un-sintered metallic powder with appropriate thermophysical parameters, we obtain depth profile of thermal effusivity for the structure. Computer simulations indicate that at 1 mm depth, layers of 50 µm thickness are detectable in SS316L.

Additive manufacturing (AM)Additive Manufacturing (AM) is a promising technique due to the scope of producing complex objects from a digital model, where materials are deposited in the successive layers as distinct from the conventional manufacturing approaches. In this study, laser powder bed fusion (LPBF)Laser Powder Bed Fusion (LPBF), a class of additive manufacturing (AM), is used to make testing samples with gas atomized 17-4 PH stainless steel (SS) powder17-4 PH stainless steel at different process parameters in argon (Ar) environment. A thorough study on powder characteristics, such as particle size distribution, powder morphology, phase formation at different atmospheres, as well as the microstructure and tensile properties of the printed parts at various energy densities were carried out. The microstructural analysis discovered the presence of columnar dendrites with complete martensiteMartensite phases regardless of the process parameters. A detailed X-ray computed tomography (CT) scan analysis on printed samples explored the correlation between the pores and energy densityEnergy density. The sample printed with adequate energy density obtained lower porosity (volume of pores: 2 × 104 to 9 × 104 µm3, compared to 2 × 104 to 130 × 104 µm3) resulting in maximum tensile strength and elongation of 770 MPa and 38%, respectively. Therefore, it is obvious that the quantity, size and shape of pores in the printed parts significantly affect the fracture mode.

The paper studies melt pool evolution in nickel-based alloyNickel-based Alloy as a function of the high-energy selective laser meltingSelective laser melting (SLM) parameters. The influence of the geometric melt pool characteristics on the development of microstructure as well as on the formation of defects is investigated. Several laser processing parameters varying in volumetric and linear energy density were chosen. The shrinkage porosity was also studied, and its dependence on the process parameters, resulting density and microstructure were determined.

During Laser Powder-Bed Fusion (LPBF)Laser Powder-Bed Fusion (LPBF), the surface formation of the selected-melted powder-bed region is subject to a melting-solidification process along the line-scans and sensitive to the process conditions. This study focuses on the surface formation of mesoscopic line-scans in LPBF and aims to investigate the effect of different process parameters, such as laser power and layer thickness, on the track morphology and surface roughnessSurface roughness. For this purpose, single-track scans were produced by an LPBFLaser Powder-Bed Fusion (LPBF) system and then were characterized under a white-light interferometer. A discrete element method and 3D thermo-fluid modeling were applied to simulate powder spreading and laser scanning. The results show that the line-scan surface morphology and the surface roughnessSurface roughness of the quasi-steady regions on the line scans are signifiscantly dependent on the process conditions both longitudinally and transversely. As a result of continuous melting in the line scans, increasing laser power and decreasing layer thickness lead to smoother surface finish, respectively.

The microstructure and the formation of dispersoidsDispersoids in Al-Mg 5xxx alloysAl-Mg 5xxx alloys under wire + arc additive manufacturing (WAAM)Wire + arc additive manufacturing (WAAM) and permanent mold casting (PM)Permanent mold casting (PM) were investigated with the aid of optical microscopy and scanning/transmission electron microscopies. In the as-deposited/as-cast condition, the grains and intermetallics in WAAM sample are finer, and its related microhardness is higher than PM sample. However, during the heat treatment at 425 ℃, the formation of dispersoids in WAAM sample is slower with bigger size and lower volume, leading to its lower microhardness than PM sample. In addition, the area fraction of the dispersoidDispersoids zone in WAAM sample is much lower than PM sample. Two types of dispersoids are observed in both WAAM and PM samples. The formation and distribution of dispersoids during heat treatment have been characterized aiming to discover the influence of fabrication processes (WAAM and PM) on the precipitation behavior of dispersoidsDispersoids.

Electron Beam Additive ManufacturingAdditive manufacturing (EBAM) is a Wire Directed Energy DepositionDirected energy deposition (DED) (W-DED) process that is receiving much more attention than other Additive ManufacturingAdditive manufacturing (AM) techniques, especially in the aeronautical sector for the serial production of metallic parts. However, this technique leads to singular microstructuresMicrostructure due to the rapid heating and cooling cycles generated during the deposition of the pieces. In this work, a first identification of the main microstructural features of Ti-6Al-4V parts manufactured by EBAM technology is performed to better understand the general characteristics of this type of parts for further improvement of this technology. The characterization is carried out by means of Optical Microscopy (OM), Scanning Electron Microscopy (SEM) observations, and Energy Dispersive X-Ray Spectrometry (EDS) analysis. The most remarkable aspects found are the formation of long columnar prior beta grains throughout several layers in the built material and the presence of many parallel thermal bands perpendicular to the thermal gradient. Quantitative measurements such as the average width of the α lamellae, the volume fraction of β phase, and the chemical composition at different positions are also accomplished. A heterogeneous microstructureMicrostructure is reported, which mainly derives from the complex and diverse thermal histories at the different positions of the deposited material. In addition, Al vaporisation is noticed. However, no significant change along the deposit material is observed for a same configuration. Next, experiments will focus on the influence of different key processing parameters on the microstructureMicrostructure and mechanical properties.

3D printing of components using a layer-based deposition of materials is referred to as additive manufacturing (AM)Additive manufacturing (AM). The ability to build complex geometry components, reduce waste and avoid assembly are the main advantages of this process. AM has been used in different industries like aerospace, medical, goods and automotive. In the aerospace, materials with high performance are needed to fulfill the requirements of the industry. Maraging steelsMaraging steel are among the materials widely used for several applications in the aerospace industry due to its high strength and toughness. These steels are hardened by the precipitation of intermetallics in a martensitic matrix. In this work, a maraging 300 steel powder was used to produce components by selective laser melting (SLM)Selective laser melting (SLM). Two heat treatments were applied to study the martensite-to-austenite reversion, HT1: 480 ℃/3 h and HT2: 980 ℃/1 h + 2 × 690 ℃/5 min + 480 ℃/6 h. The microstructural characterizationMicrostructural characterization was assessed by optical microscopy (OM), scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). As-built condition revealed a cellular and dendritic morphology with segregation of Ti, Ni and Mo to the grain boundaries. Direct aging treatment does not erase the typical AMAdditive manufacturing (AM) morphology, but a solubilization at 980 ℃/1 h was capable of fully recrystallize the microstructure. The EBSD analysis showed the increase of reverted austenite for the HT2 and this was attributed to the cycling reversion.

Intermetallic titanium aluminide (TiAl) alloysXE “TiAl alloy” are considered attractive materials for high-temperature applications in aerospace, automotive, and energy industries. Additive manufacturingXE “Additive manufacturing (AM)” is a promising way of producing complex TiAl-alloy parts; however, it remains challenging due to brittleness of this alloy. While high-temperature preheating can mitigate cracking during selective laser meltingXE “Selective Laser Melting (SLM)”, the microstructure of TiAl-alloys still needs to be optimized to achieve better mechanical performance. In this work, multiple laser exposures were used during selective laser melting of TiAl-based alloy to tailor its microstructure. Applying additional laser exposure of up to 20 times per layer induced an in situ heat treatmentXE “in situ heat treatment”, which allowed to modify volume fraction and size of different phases. Microstructure, phase and chemical composition, and hardness of TiAl-alloys were investigsated with regards to several laser exposures during the selective laser melting process.

Understanding the deformation mechanisms present near grain boundaries in polycrystalline hexagonal alloys will aid in improving modeling methods. Ti-5Al-2.5Sn samples were tensile tested at 296 and 728 K, and slip behavior was assessed near grain boundaries. From the EBSD measurements of grain orientations, various metrics related to the slip systems, traces, residual Burgers vectors, and grain boundary misorientation were computed for boundaries showing evidence of slip transfer and boundaries showing no evidence of slip transfer. This work is compared to a similar study of an aluminum oligo-crystal to aid in understanding the differences in slip behavior near grain boundaries in HCP and FCC crystal structures.

The continued evolution in nanoelectronics and nanophotonics has been made possible by the recent developments in Atomic Layer DepositionAtomic Layer Deposition (ALD) and Atomic Layer EtchingAtomic Layer Etching (ALE). While uniform deposition of conformal films with controllable thickness is a key feature of Atomic Layer Deposition, Atomic Layer Etching offers the advantages of controlled removal of chemically modified areas. Various case studies of the applications of these technologies in dielectricsDielectrics, metals and diffusion barriersDiffusion barriers will be discussed.

To prevent damage to components and tools during deep-drawingDeep drawing processes, the use of lubricants is recommended. Depending on the demands of given processes and materials, different types of lubricants such as mineral oils, synthetic oils, emulsions or waxes are generally used. However, these lubricants often contain substances that are harmful to human health and environment. Additionally, they must be applied before forming operations and washed off afterwards to enable subsequent processes. A novel tribological system using volatile lubricants such as CO2 or N2 has been developed and tested to counteract these disadvantages. The operating principle of this tribological system is based on the injection of volatile media into the friction zone under high pressure to ensure the separation of tool and sheet metal surface. This contribution presents the latest findings on the laser drillingLaser drilling of microholes and on process stability of the dry deep-drawingDeep drawing process under endurance conditions.

The understanding of the surface behavior, interaction, wettability, and topographies of surfaces with fluids is very important to remove impurities from the devices and components and to develop washing fluids to clean large area surfaces. We synthesized nano particle filled composites by wet and semi-wet techniques to achieve hydrophobicityHydrophobicity and hence the lotus effectLotus effect. NanocompositesNanocomposites with different composition of polymers doped with titania nanoparticles were studied to evaluate effects on wettability. Light scattering methods were used to study the absorptions and particle size. The contact angleContact angle and hydrophobic characteristics were very composition dependent in thin film composites. At certain compositions, we observed that material showed very high anisotropy in droplet shapes which diminished with loadings of nanoparticles. These composites did not show any change in hydrophobic characteristics when exposed with ultraviolet radiation.

An analysis of the temperatureTemperature dependence of the energy gapEnergy Gap in semiconductorsSemiconductors is presented. Its influence on solar cellSolar Cells performance is examined for various semiconductor candidates. In particular, semiconductors belonging to groups IV, III–V, II–VI, as well as perovskitesPerovskites are considered. The results presented in this study are anticipated to be of direct applications to the utility of solar cells in space as well as in the design and manufacture of tandem solar cellsSolar Cells.

The effect of thermomechanical rolling schedules on the development of crystallographic texture, mechanical properties, and SCCStress Corrosion Cracking (SCC) susceptibility were studied in an API X70API X70 steel. The rolling temperatures and the magnitude of deformations (rough and finish rolling) were highly influential on the development of crystallographic textureTexture and the resulting mechanical properties and SCCStress Corrosion Cracking (SCC) performance. Complete rolling above RLT (Tnr) resulted in the formation of large, equiaxed upper bainite and the highest yield strength and ultimate tensile strength. Finish rolling in the two-phase region increased the polygonal ferrite formation and deteriorated mechanical properties of the rolled steels. When finish rolling above the Ar3, an increase in the magnitude of the initial rough rolling deformation increased the proportion of granular bainite within the structure. Optimising the rolling strategy has shown to positively affect SCCStress Corrosion Cracking (SCC) performance.

Prior researchMagnetic Augmented Rotation System (MARS) conducted by the team at NJIT has shown that contactless torque transmissionContactless torque transmission is possible and effective. In recent years, there has been significant development in materials, material systems, and materials processing for applications in contactless transmission. In minimizing material wear and tear due to minimal or zero friction, gearless systems require no lubrication, offer extended shelf-life and exhibit minimal noise. By utilizing 3D printing3D Printing technologies such as fused deposition modeling and stereolithography, we are able to rapidly test new concepts and ideas. Growth opportunities of this evolving technology are summarized.

Unobtrusive magneto-reception can enable innovative applications in diverse scenariosMünzenrieder, Niko ranging from the interaction of humans with virtual objects to the controlledCantarella, Giuseppe movement of micro-robots. The required bio-compatible magnetic sensorSensor technology systems have to be cheap and able to conform to the movement of reconfigurable surfaces and biological tissue,Petti, Luisa while providing excellent performance. The key to realize such systems is the integration ofCosta, Júlio magnetic sensorsSensor technology with on-site conditioningConditioning electronics directly on large-area plastic substrates. In fact, ad-hoc optimized oxide thin-film transistorsThin-film transistors provide a technology platform which is not affected by mechanical deformation or magnetic fields and can hence be used to boost the performance of magnetic sensorSensor technology systems through front-end conditioning. Flexible oxide conditioning Conditioningcircuits provide voltage gains close to 50 dB at operation voltages down 1.7 V while bent to radii <4 mm. Fully flexible Co/Cu giant magnetoresistance sensorsSensor technology, Wheatstone bridges and amplifiers can be integrated on a single polymer foil and result in a 50 $$\upmu $$ μ m-thin conformal system with a 25 V/V/kOe sensitivity.

The excessive consumption of lithium and cobalt with increasing demand for lithium-ion batteries (LIBs) poses critical challenges in sustaining the cost-effectiveness of LIBs in the future. Among post-LIB systems, rechargeable aluminum batteries are particularly promising due to favorable properties including low material cost, high abundance, and high theoretical capacity. Most aluminum batteries utilize expensive alkylimidazolium/pyridinium chloride-based chloroaluminate ionic liquids. This greatly limits the commercialization of such systems, particularly for large-scale applications. Herein, we report a high-performanceHigh-performance aluminum battery made of graphene nanoplatelets as the cathode and low-cost aluminum chloride-trimethylamine hydrochloride (AlCl3-TMAHCl) ionic liquid as the electrolyte. The battery can be cycled for a few thousand cycles while delivering excellent specific capacity (~134 and ~80 mAh g−1 at 2000 and 4000 mA g–1, respectively) and coulombic efficiency. Through fundamental considerations, we demonstrate that Al/graphite battery employing AlCl3-TMAHCl can achieve the highest cell-level energy density while maintaining comparable power density compared with conventional chloroaluminate ILs.

The present study investigates the physicochemical properties of cost-effective AlCl3-ureaAlCl3-urea ionic liquid analogs (ILAs) for aluminum (Al)-ion batteries. The neutral and the acidic regions for AlCl3/urea molar compositions were investigated using nuclear magnetic resonance spectroscopy (NMR), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS) to determine the speciationSpeciation of ionic moieties, electrochemical stabilityElectrochemical stability, and ionic conductivityIonic conductivity of this complex system. The physical characterization shows that only 1.2–1.5 molar compositions are suitable for aluminum-ion batteries at room temperature, while 1.3 results in the highest ionic conductivity. The NMR results indicate that Al2Cl7– is the dominating species for electrodeposition of aluminum at higher molar composition compared with AlCl2·(urea)2+, while the relative amount of AlCl4– remains almost unchanged across investigated compositions. The aluminum-ion batteryAluminum ion battery prepared using aluminum anode and graphene nanoplateletsGraphene nanoplatelets cathode delivered a specific capacity of 60 mAh g–1 with 1.4 molar composition ILAs at 400 mA g–1.

The heat transfer ability of the mold fluxMold flux is crucial for balancing the heat fluxHeat flux between the slab and mold. The double hot thermocouple techniqueDouble hot thermocouple technique (DHTT) is widely used for the qualitative determination of the heat transfer performance of the mold fluxMold flux due to its advantages of rapid in-situ testing. However, the traditional DHTT cannot determine heat fluxHeat flux quantitatively, which limits the development of DHTT in the field of heat transfer measurement. In the current study, the in-situIn-situ quantitative method quantitative investigation method based on DHTT was, for the first time, proposed to determine the heat transfer performance of mold fluxMold flux. Herein, the heat fluxHeat flux of four mold fluxesMold flux with different Al2O3/SiO2 mass (A/S) ratios was estimated by using the new DHTT. The result showed that the heat fluxHeat flux decreases with increasing A/S ratio, which is consistent with the result of the parallel-sided plate method.

The electrochemically deposited liquid metal (Me = Ca, Li, or their alloys) in the molten chloride works as powerful reductant for TiO2 or other metal oxides; however, the electrolysis efficiency should be enough high if much lower oxygen level in metal phase was required. A detailed understanding of the cathodic behavior is necessary to control and optimize the electrolysis. In this study, to clarify the morphological and thermal characteristics of a cathodic electrode in a molten MeCl melt, we simultaneously performed electrochemical measurements and thermal measurements using an ultrafine thermocouple inserted inside a Mo electrode. Changes in the electrode interface were recorded at 500-μs intervals using a synchronized high-speed digital camera. It was possible to trace the change in the electrodeposition pattern in each potential quickly and sensitively, which was difficult to determine in only the electrochemical potential-current response.

Low C-steel to Fe-7%Al alloy dissimilar joint by electron beam weldingElectron beam welding (EBW) was carried out using oscillating beam, without oscillating beam and by increasing welding speed condition. X-ray radiography technique at sub-micron resolution was employed to study the effects of scanning parameters on the defect formation. Detection and quantification of defects within welds were subsequently carried out from radiography images by image processing, segmentation of images and pattern recognition. X-ray radiography images showed the presence of porosityPorosity, wormhole and lack of fusion-type defects in the dissimilar joints. Quantitative analysis of weld defects demonstrated that beam oscillationBeam oscillation provides better quality weld by decreasing approximately 58% porosityPorosity compared to its non-oscillating counterpart and 73% compared to higher welding speed. Wormhole and lack of fusion defects were observed at other two conditions, which did not observe in welds produced by beam oscillation.

A study on the bioactivity and mechanical properties of the porous hydroxyapatiteHydroxyapatite–hardystoniteHardystonite–PCL was performed, and the results were compared with the non-modified porous hydroxyapatiteHydroxyapatite. Different apatite morphologies were observed in these two modified and unmodified scaffoldsScaffold. The compression strength, modulus and toughness of the modified scaffoldsScaffold showed 104, 14 and 38% improvement compared to unmodified scaffoldsScaffold. This can be ascribed to the main role of thin polymerPolymer-ceramic coatingCoating layer applied on the surface of hydroxyapatiteHydroxyapatite scaffoldsScaffold on the mechanical and biological properties. These composite scaffoldsScaffold showed a great potential to be used for bone tissue engineering application.

As new structural and functional materials, porous materials have unparalleled advantages compared to dense materials because of their special pore structure. The powder metallurgyPowder metallurgy technique was utilized to prepare titanium foams by adding space holders to generate pores and FeV80 to modify the structure and propertiesProperty of the materials. The results show that the TixVy (x + y = 1) phase exists in the sintering product after adding FeV80 powder. The content of FeV80 increases from 0% to 12%, resulting in the initial yield strengthYield strength increasing from 190.08 MPa to 380.82 MPa; when the content of FeV80 is increased to 16%, the initial yield strengthYield strength decreases to 331.77 MPa. Therefore, the improvement created in the mechanical properties of the porous titanium by adding ferrovanadiumFerrovanadium alloy is highly significant.

New ceramic materials with layered crystal structuresLayered crystal structure and chemical formulaIn1x(Ti1/2Zn1/2)1-xO3(ZnO)m In1+x(Ti1/2Zn1/2)1-xO3(ZnO)m (x = 0.5; m = 2, 4 and 6), hereITZO named ITZO-II, ITZO-IV and ITZO-VI, have been synthesized by solid-state reaction method. The phase characterization, phase stability with temperature and their microstructureMicrostructure have been studied by X-ray powder diffractometry (XRD) and scanning electron microscopy (SEM). The XRD showed a hexagonal single phase at 1200 °C whereas, at higher temperatures (1300 and 1400 °C), they decompose in secondary phases such as the In2Zn7O10 solid solution and starting material traces. SEM micrographs showed an increase in grain size as the temperature of sintering increases, reducing the porosity and increasing the bulk density. Here, the dielectric spectra in a wide range of temperatures and frequencies are reported. The permittivity results seem to indicate a classical paraelectric behavior in this class of layered structural ceramic compounds.

To study the technological possibility of dehydrationDehydration from zinc leaching residueZinc leaching residue by microwave heating, the temperature increasing characteristics of zinc leaching residue were studied. At the same time, the influences of the different material quantities, different drying time, and different microwave powers on the relative dehydration rate of zinc leaching residue were investigated, respectively. The results showed that the control temperature of 100 ℃, the microwave power of 750 W, the mass of 50 g, the drying time of 21 min had the best drying effect, and the water removal rate was 95.45%. It was found that the heating rate is directly proportional to the power and inversely proportional to the material quantity.

Willemite Willemite is currently recognized as a bio-ceramic Bio-ceramic material for bone repair and bone tissue engineering applications. In this study, pure willemite Willemite powder was fabricated by mechanical alloying method. The starting materials were zinc oxide and silicon oxide. The results showed that pure willemite Willemite powder can be produced following 20 h of milling and subsequent sintering at 900 ℃ for 3 h. The obtained willemite Willemite powders had crystallite size and particle size in the range of 143–147 nm and 300–500 nm, respectively.

To improve the thermal shock resistanceThermal shock resistance of ladle lining castable, silica-free alumina–spinel castablesAlumina–spinel castables with an extensive range of calcium aluminate cement contentCement content (2–10 wt%) were prepared and the properties were investigated. The results showed that the card-house structures formed by the hexagonal flake calcium hexaluminate grains and the appropriate density of microcracks caused by the expansive reflection of calcium hexaluminate formation after firing at 1550 ℃, which were beneficial to strengthen the aggregate-matrix combination and alleviate thermal stress. Consequently, the performance of the castables, including the retained moduli values and hot modulus of rupture, reached to the optimal values after 3 thermal cycles while 5–8 wt% cement was added. But while further increasing the cement contentCement content, these performances of the castables were degraded by the excessive volume expansion and density matrix due to the formation of calcium hexaluminate and the space occupation of calcium dialuminate respectively.

TheMolten salt deoxidation Fe-FeAl2O4 composite materialFe-FeAl2O4 composite material wasThermodynamic prepared by molten salt electro-deoxidation method. It used mixed Fe2O3 and Al2O3 powder for tableting, and served as cathode electrolysis. The standard Gibbs free energy change (ΔGΘ) and theoretical decomposition voltage (EΘ) of each reactant in the system were calculated by FactSage. The results showed that the EΘ was in the range of −1.01 V to −2.31 V at 800 ℃, Fe2O3 reduced to FeO, formed FeAl2O4 spinel phase with Al2O3, and the remaining FeO continued to reduce to metallic phase Fe. By using FactSage to analyze the phase diagram of FeO-Al2O3 binary system, it can be determined that the molar ratio of Fe2O3 and Al2O3 was 2:1 and the best reaction temperature range for preparing Fe-FeAl2O4 composite materialFe-FeAl2O4 composite material was 800–900 ℃.

Having superior mechanical properties, nickel-titanium (Ni–Ti) based shape memory alloys are extensively used to make bio-implants. The existing literature suggests several surface modification techniques, including surface coatingCoating, for improving the bio-compatibility by reducing leakage of nickel from surface layers. Herein, an environmentally-friendly surface coatingCoating method, based on the concept of near-dryNear-dry electric discharge machining (ND-EDM) process, was explored to deposit the titanium nitride (TiNTitanium Nitride (TiN)) layer. Repeated spark discharges occurring in a two-phase dielectric medium of water and nitrogen gas were used for depositing the layer. The effect of process parameters like peak-current and pulse-on time on the surface integritySurface integrity of deposited layers was evaluated. The deposited surfaces were characterized using the X-Rays diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and atomic force microscopy (AFM) techniques. The results show that the TiNTitanium Nitride (TiN) layer can successfully be deposited onto Ni–Ti substrate.

Ti-5553Ti-5553 (Ti-5Al-5Mo-5V-3Cr-0.5Fe) is a newly developed near β titanium (Ti) alloy with excellent fatigue performance and corrosion resistance. Hence, it is of significant importance in several high-performance aerospace applications such as landing gear components and helicopter rotors. The machinability of Ti-5553Ti-5553 is low owing to its high strength at elevated temperature, low thermal conductivity and high chemical reactivity. Although there is a profound knowledge about the machinability of α + β Ti alloys (typically Ti-6Al-4V), there is a lack of understanding regarding the surface microstructure evolutionMicrostructure evolution during machining of Ti-5553Ti-5553. This paper presents experimental investigations on the microstructure evaluation in the hole surface produced from drilling of Ti-5553Ti-5553. A series of high-speed drillingHigh-speed drilling tests were conducted to evaluate the influence of cutting conditions on the hole surface microstructure alternation in relation to the cutting temperatureCutting temperature. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) technique were used to characterize the hole surface microstructure evolutionMicrostructure evolution. The precipitation of new α phase from β matrix in the hole surface was observed in dry drilling; however, this phenomenon was not detected in wet drilling with a coolant supplied.

Process-structure-propertyStructure-Property relationships are the hallmark of materials science. Many integrated computational materials engineering (ICMEICME) models have been developed at multipleTran, Anh length-scales and time-scales, whereUncertainty quantification uncertainty quantification (UQ) plays an important role in quality assurance. In this paper, we applied our previous work [39] to learn a distribution of microstructure features that areWildey, Tim consistent in the sense that the forward propagation of this distribution through a crystal plasticityCrystal plasticity finite element model (CPFEM) matches a target distribution on materials properties, which is given beforehand. To demonstrate the approach, DAMASK and DREAM.3D are employed to construct Hall-Petch relationship for a twinning-induced plasticity (TWIP) steel, where the average grain size distribution is inferred, given a distribution of offset yield strength.

Data-driven analytical clusteringClustering and visualization techniques were applied to the dataset of 9%9% Cr alloy Cr experimental alloy data generated through the eXtremeMAT project. Techniques and results were compared with the resulting clusters obtained through similar analytical techniques on previous and reduced versions of the dataset. The principal components were generated in order to reduce the dimensionality of the complex dataset and to visualize the underlying trends in the data. Partitioning around medoids was performed on the resulting principal components to determine relevant clusters. Domain knowledge labels were further applied to the principal components to compare the labels with the trends identified through the clusteringClustering methods. The clusters can be used to compare the tensile properties of the alloys and to reduce the variation in the dataset.

The strengthening mechanism of the 2000 series aluminum alloy has been studied using neural networks. We have constructed a neural network for the simultaneous prediction of multiple mechanical properties, including ultimate tensile strength, tensile yield strength, and elongation at break. The replica-exchange Monte Carlo method, an improved Markov chain Monte Carlo (MCMC) method, has been applied for Bayesian learning of the optimal neural network architecture and hyperparameters. The obtained neural network, combined with the thermodynamic analysis using the Thermo-Calc software, enables us to identify a dominant combination of additive elements and heat treatments for strengthening alloys. We have also addressed an inverse problem for optimizing the process parameters. The approach we propose will accelerate the design of high strength alloys for high-temperature applications.

Process-structureProcess-structure linkage is one of the most important topics in materials science due to the fact that virtually all information related to the materials, including manufacturing processes, lies in the microstructure itself. Therefore, to learn more about the process, one must start by thoroughly examining the microstructure. This gives rise to inverse problems in the context of process-structureProcess-structure linkages, which attempt to identify the processes that were used to manufacturing the given microstructure. In this work, we present an inverse problem for structure-process linkages which we solve using asynchronous parallel Bayesian optimizationBayesian optimization which exploits parallel computing resources. We demonstrate the effectiveness of the method using kinetic Monte CarloKinetic Monte Carlo model for grain growthGrain growth simulation.

Microstructure reconstructionMicrostructure reconstruction is a long-standing problem in experimental and computational materials science, for whichTran, Anh numerous attempts have been made to solve. However, the majority of approaches oftenTran, Hoang treats microstructure as discrete phases, which, in turn, reduces the quality of the resulting microstructures and limits its usage to the computational level of fidelity, but not the experimental level of fidelity. In this work, we applied our previously proposed approach [41] to generate synthetic microstructure images at the experimental level of fidelity for the UltraHigh Carbon Steel DataBase (UHCSDB) [13].

DislocationDislocations dynamics simulations often reveal interesting phenomena in regard to material deformation, which may not be captured by experiments. In this work, we investigate the effect of dislocationDislocations dipolesDipoles on plastic material properties under different dipole configurations (i.e. the distance between active glide planes, and the signs of the two dislocations) using a 3D Discrete Dislocation Dynamics code. The simulations show that a dipole is causing a hardeningHardening effect when the Burgers vectors of the dislocationsDislocations forming the dipole are of opposite sign and causing a hardening/softeningSoftening effect when they are of the same sign. The distance between the two neighboring dislocations was also affecting the proportional limit for the material. Such hardening or flow stress results, as in this study, can be incorporated in larger-scale modeling work.

The unplanned slabUnplanned slab is the open orders slab produced by the steelmaking-continuous casting process, which will increase the inventory cost of enterprises. The unplanned slabUnplanned slab allocationAllocation problem is to reasonably assign the unplanned slabsUnplanned slab to the hot rolling supplementary orders, steelmaking supplementary orders, or customer orders in a given period. It can be considered as an extension of the multiple knapsack problemMultiple knapsack problem. Therefore, a 0–1 integer programming modelModel is established to minimize the cost of differences between unplanned slabUnplanned slab and order specification. In this paper, a decomposition method of problem solving process, an adaptive measurement method of order priority in different scenarios, and an improved dynamic programmingDynamic programming algorithm considering the local search strategy are proposed for the unplanned slabUnplanned slab allocationAllocation. The testing cases with data from a steel plant show that the optimization algorithm for the unplanned slabUnplanned slab allocationAllocation is superior to the manual one in terms of solution quality and calculation time.

Kesterite (CZTS, Cu2ZnSnS4Kesterite (CZTS, Cu2ZnSnS4)) is a quaternary chalcogenide which structural complexity leads to polymorphism and numerous kinds of disorder in cation sites, with interesting effects on thermoelectric properties. Tetragonal kesterite faces an order-disorder phase transition from I-4 to I-42m crystal structures around 533 K, which causes a sharp increase in the Seebeck coefficientSeebeck coefficient. The degree of order in the crystal structure determines the entity of this enhancement, locally influencing the steepness of the trend of thermopower in the transition region. The presence of secondary phasesSecondary phases reduces the effect of the transition as well as causing a progressive reduction of the Seebeck coefficientSeebeck coefficient. The present results show that a measurement of Seebeck coefficientSeebeck coefficient provides direct and distinctive information on the degree of order and phase purity of kesterite samples, integrating results of Raman spectroscopy and X-ray diffraction.

TitaniumTitanium foam has good biocompatibility and mechanical properties, and is often used as a bone replacement material. CobaltCobalt can improve the density of titanium foam cell walls and help improve mechanical properties. In this paper, the effect of different cobalt contents on the microstructure of titanium foam was studied. Six sets of comparative experiments with different cobalt contents were carried out. The sintering temperature was 1100 °C and the holding time was 1.5 h. The samples were subjected to metallographic and SEM inspection. Between 0 and 10%, with the increase of cobalt content, the pores gradually become denser, which helps to improve the mechanical properties. Excessive cobalt powder will lead to the closure of microscopic pores, and the connectivity between the pores becomes poor. When the cobaltCobalt content increases from 10 to 14%, the porosityPorosity of titanium foam decreases from 45% to about 20%.

GraphiteGraphite is a key material in the design and operation of a wide range of nuclear reactors because of its attractive combination of thermal, mechanical, and neutron interaction properties. In all its applications, the microstructural evolution of nuclear graphite under operating conditions will strongly influence reactor lifetime and performance. However, measuring the 3D microstructural characteristics of nuclear graphiteGraphite has traditionally faced many challenges. X-ray tomographic techniquesX-ray tomography face limitations in achievable resolution on bulk (mm-sized) specimens while serial sectioning techniques like FIB-SEM struggle to achieve adequate milling rates for tomographic imaging over representative volumes. To address these shortcomings, we present here a multiscaleMultiscale, targeted, correlative microstructural characterization workflow for nuclear graphite employing micro-scale and nano-scale x-ray microscopy with a connected laser milling step in between the two modalities. We present details of the microstructure, including porosityPorosity analysis, spanning orders of magnitude in feature size for nuclear graphiteGraphite samples including IG-110.

Tailoring the fraction and distribution of microstructural features computationally to achieve an optimized strength-ductility combination in heterogeneous materials is gaining importance. These microstructural features include grain size (GZ), geometrically necessary dislocation (GND), and crystallographic texture, among others. However, it is challenging to find the influence of an individual microstructural feature on the mechanical response experimentally due to cost limitations. In the current work, computational approaches and comprehensive statistical parametric study using response surface methodology (RSM) were combined to estimate the optimum fraction and distribution of microstructural features for coveted mechanical properties.

In the current study, a stochastic mesoscopic model was applied to predict the evolution of the A356 microstructureMicrostructure (e.g., dendritic morphologies and columnar-to-equiaxed transition formation) in a 2-Zone induction melting and solidification furnace. The influence of process and material parameters on microstructureMicrostructure, such as initial melting temperature, ultrasonic stirring and cavitation, fluid flow conditions, cooling rate, temperature gradient, and nucleation and growth kinetics parameters for both equiaxed and columnar phases, is studied. In addition, the initial transient of the macro-segregation of silicon during solidification of A356 in the crucible is also simulated. The results will be helpful for determining the solidification structure, mushy zone evolution in the crucible and assist in developing of comprehensive solidification maps of alloys used in additive manufacturing.

ANozzle injection mode coupled three-dimensional numerical model combining fluid flow, heat transfer, and solidification has been established to study the effect of two types of nozzle on the internal quality of LZ50 steel in a φ 690 mm sized continuously cast round bloom. The model is validated by measured data of the strand surface temperature for plant tests. According to the simulation and experimental results, it is found that the larger tangential velocity on meniscus and the higher vortex depth in the six-port nozzle is beneficial to melting mold powder and the floating removal of inclusions. When the injection mode is the six-port nozzle, the level fluctuationLevel fluctuation was an effective control to avoid slag entrapment, and the washing effect with multiple swirling flow reinforces both the heat exchange through the solidification front and the dendrite re-melting or fragmenting, stimulating the formation of an equiaxed crystal at the round bloom center. As the injection mode changes from the five-port nozzle to the six-port nozzle, the superheat degree in the round bloom center at the mold exit decreases by 9.3 K, which is one of the resulting increase in the center equiaxed crystal ratioCenter equiaxed crystal ratio is about 4.3% and the length of columnar decreases by 20 mm. A weaker impingement of the outlet flow on the shell has been observed as well, which can be expected to eliminate the popular subsurface white band phenomenon with an even shell thicknessShell thickness in the mold region. This suggests that the six-port nozzle can effectively improve the quality of large round bloom casting.

A three-dimensional numerical model coupling the electromagnetic fieldElectromagnetic field, fluid flowFluid flow, and level fluctuation has been developed to investigate the flow behavior of molten steel in a slab continuous casting mold for interstitial-free (IF) steel. According to the industrial and modeling results, the swirls are generated on the cross-section due to the electromagnetic force (EMF) and its number relies on the magnetic pole pairs of electromagnetic fieldsElectromagnetic field. With the increase in current frequency, the EMF reaches the maximum at the current frequency of 4.5 Hz and then gradually decreases. When the current intensityCurrent intensity increases from 0 to 600 A, the rate of slag entrapmentRate of slag entrapment related to the billet defects is decreased from 7.46 to 1.09%, but it increases to 6.09% when the current intensityCurrent intensity reaches 650 A. The study suggests that the optimized current intensityCurrent intensity of mold-electromagnetic stirring (M-EMS) can effectively prevent surface or subsurface defects for clean steel production.

Liquid metal batteriesLiquid metal batteries are discussed as stationary electrical energy storage for renewable energies, in order to compensate their fluctuating supply of energy. A liquid metal batteryLiquid metal batteries consists of three different liquids, which stay segregated due to density differences and mutual immiscibility. The negative electrode is the low-density liquid metal, and in our case sodium, a medium density molten salt, is the electrolyte and positive electrode is a high-density liquid metal. For the latter, Sb–SnSb-Sn alloy and Sb–Bi alloys are selected. However, one issue is the compatibility of structural materials with the used liquids. In a first step, the behavior of potential structural materials in Sb3Sn7 and SbBi9 at the temperature of 450 °C up to 750 h was tested. The results showed that the corrosionCorrosion in SbBi9 was significantly less than in Sb3Sn7 and the most promising materials were molybdenum meta and Max-phase coatings.

An engineering model is presented for a self-consistent calculation of the growth of an oxide filmFilms in circulation loops with a heavy liquid metal coolantHeavy liquid metal coolant and concentrations of impuritiesImpurities using STAR-CCM+ software complex. The modeling of thermohydraulic and physicochemical processes is based on solving the associated three-dimensional equations of hydrodynamics, heat transfer, convective-diffusive transport, and the formation of chemically interacting impurityImpurities components in the coolantCoolant volume, and on the surface of steels. The parabolic constant, which is determined by the degree of steel oxygen consumption, obviously significantly depends on this steel grade. For a more adequate justification of the evolution of the oxide filmFilms, a semi-empirical model is proposed for using the empirical parameterization of the parabolic constant not only in the equation for changing the thickness of the oxide filmFilms but also in the mass balance equation associated with it.

Corrosion studies in high-temperature liquid Pb of conventional materials such as Fe–Cr and Fe–Cr–Ni steels for LFRs have demonstrated that they are prone to corrode affecting their structural integrity. Corrosion is minimized by using oxygen in Pb to form a protective Fe–Cr oxide layer on steels, but its protectiveness works well only up to 450–480 °C limiting their applicability in LFRsLFR. The present work shows preliminary corrosion results of alternative materials (Ni alloys, FeCrAl ODS, Zr and Mo alloys, and SiC) for potential use in Pb, obtained by ENEA and Westinghouse Electric Company. Tests were performed in static Pb at 550 and 750 °C and different oxygen concentrations. The results demonstrated the potential availability in Pb of some of these materials and confirmed the key influence of oxygen on corrosion, imposing oxygen controlOxygen control in Pb coolant to prevent critical damage of materials. About oxygen controlOxygen control, some ENEA activities will be illustrated.

The solutionSolution of elements from metallic alloys is analysed and compared with observations for steels and nickel-based alloys after exposure to lead-based liquid alloys or liquid tin. Furthermore, the influence of dissolved oxygen and formation of intermetallic compounds are addressed.

We analyze an engineering model for a self-consistent calculation of the growth of an oxide filmOxide film in circulation circuits with a heavy liquid metal coolant and concentrations of impuritiesImpurities (oxygen, iron, magnetite) from the point of view of possible uncertainty in determining the activity of oxygen. The modeling of thermohydraulic and physicochemical processes is based on solving the associated three-dimensional equations of hydrodynamics, convective-diffusive transport, and the formation of chemically interacting impurityImpurities components in the coolant volume and on the surface of steels. Model calculations of the influence of the uncertainty of oxygen activity on the rate and integral yield of iron, which under the given conditions of the oxygen regimeOxygen regime after interaction with oxygen determine the appearance of magnetite. It is numerically demonstrated that in the saturationSaturation mode, there is a model-independent characteristic, which is determined by the parabolic constant and thickness of the oxide filmOxide film characteristic of steel.

This work focuses on the microstructure evolution upon rotary friction weldingRotary Friction welding of Al 6061 to mild steel and resulting joint strength. Material deforms plastically during rotary friction weldingRotary Friction welding; however, temperatures are low enough to prevent melting, which limits intermetallic compound formation. Displacement-controlled rotary friction weldingRotary Friction welding of circular workpieces is performed with combinations of three friction times (48, 24 and 16 s) and two rotation speeds (1200 and 1400 rpm). Significant grain refinement is observed at the centre on Al 6061 side, which indicates dynamic recrystallizationDynamic recrystallization. However, only recovery is observed at the mild steel side, which is attributed to low temperatures. The maximum joint strength of 136 MPa is achieved. The fractured surfaces from tensile tests reveal sticking of Al 6061 on mild steel at the centre region. The fractured surfaces suggest ductile fracture in the centre region and brittle fracture close to the periphery.

The crash boxes used in cars are the connection elements that absorb the impact energy that occurs in the event of an accident and provide the energy released by the accident to the car at the minimum level (Sharifi et al. in Thin-Walled Structures 89:42–53, 2015). In the study, the effects of heat treatments on the mechanical properties of the crash boxes were investigated in order to reach the optimum levels of AA6060 alloy box profiles produced by extrusion method. F, T4, T5, T6, and T7 heat treatments were applied to crash boxes. As a result of compression loads, force–displacement graphs were obtained and total absorbed energies were calculated from these graphs. Samples that were able to absorb the highest energy in samples produced for use in crash boxes were obtained in T6 heat treatment.

Bulk metallic glasses (BMGs) are very attractive to a range of micro-electronic applications including sensing elements, precision optics, and micro-geared motors due to their high strength, elasticity, corrosion resistance, and soft magnetic properties. Although joining BMGs to dissimilar materials to manufacture interconnects for micro-electronic devices is a great challenge, micro-friction stir spot welding (µFSSW) is a novel solid-state joining process which makes it a strong candidate for joining BMGs or BMGs to other crystalline materials to fabricate various types of interconnectsBMG /Al interconnects. However, studies on the dissimilar µFSSW of BMGs to aluminum (Al) alloys are limited. This paper presents experimental investigations on interface formation in µFSSW of dissimilar Zr-based BMGs (i.e. LM105) to 6061 Al alloys. A series of µFSSW of dissimilar 1.5 mm thick LM105 BMGs-to-6061Al-T6 sheets trials were conducted and the stir zone temperature was measured. The obtained joint cross sections were characterized by scanning electron microscopy equipped with energy dispersive X-ray spectroscopy, and the effect of µFSSW conditions on the joint interface’sJoint interface microstructure microstructure evolution was evaluated. It has been found that the BMGs materials were stirred into the Al side in the stir zone and reacted with the Al to form the Al-rich phase.

Ag sinter-joining isThermal cycling test an ideal connection technique for next-generation power electronics packaging due to its excellent high-temperature stability and excellent thermal conductivity. In this work, we applied Ag sinter-joining to die attachDie attach of power electronics and focused reliabilityReliability of Ag sinter-joining under a harsh thermal cycling condition, which ranges from − 50 to 250 ℃. The bonding quality of as-sintered die attachDie attach had a shear strength of over 45 MPa and remained over 25 MPa after a 500-cycle test. However, the shear strength drastically degraded to less than 10 MPa due to a failure of metallization layer detachment between dummy chip and sputtering layer after 750 cycles. Meanwhile, thermal resistanceThermal resistance of die attachDie attach with different bonding materials was also evaluated by a T3ster, which suggests the Ag sinter-joining owns a superior property of thermal conduction than the traditional solder joining. This investigation indicates that the Ag sinter-joining has a long lifetime under a severe operating condition of power electronics.

The adoption of fossil-based hydrocarbon polymer composites has been successful in both the automotive and aircraft industries and is rapidly expanding into buildings and civil infrastructure. One challenge to broader adoption of polymer composites in buildings and civil infrastructure is a limited ability to model the synergistic effects of the combined physical/chemical processes of environmental exposure and mechanical loading. Unlike other building materials, long-term experience and field performance data of polymer composites in buildings and civil infrastructure applications do not exist. The first and largest composite building system used in a high-rise exterior in the USA is the facade of the San Francisco Museum of Modern Art (SFMOMA) completed in 2015. Since historical, experience-based service life models for composite building applications are not available, it is crucial to build multi-physical-based models in order to predict composite service life performance on a semi-centennial or centennial time scale. This study is to build a physics-based model to predict synergistic effect of environmental exposure to damageDamage of the composite. Based on the authors’ previous UVUV/moistureMoisture exposure experiment-computational study, this extended study couples degradation-induced material weakening to continuum damage model. Results of this study indicate that the synergistic effect of combined UV and moisture exposure on composite material degradation is more severe than simple linear superposition of each exposure’s damage. A comparison and analysis of UV and moisture exposure degradation mechanisms indicate that these environmental exposures caused material degradation by weakening the polymer matrix, along with weakening the interface between the polymer matrix and fiber reinforcing yarns. Moreover, the interface weakening is more critical than the former one.

With fossilBoot, Tim fuels being phased out and growing global interest in a hydrogen economy, there is demand for re-purposingRiemslag, Ton existing pipelines for transportation of hydrogen gas. However, hydrogen embrittlementHydrogen embrittlement (HE) can limit pipeline steel’sPipeline steel performance. In this study, the effect of hydrogenReinton, Elise on the mechanical properties of an X60 base metal (polygonal ferrite/pearlite) and its girth weld (acicular ferrite/pearlite) was measured with a novel slow strain rateLiu, Ping tensile (SSRT) test in which hollow pipe-like specimens were internally pressurised with nitrogen and hydrogenWalters, Carey L. gas from 0 to 100 bars. Results showed that exposure to H2 gas at 100 bars reduced the ductility ofPopovich, Vera the base metal by up to 40% and the weld metal by 14%. Reduction in cross-sectional area (%RA) reduced by up to 28% in the base metal and 11% in the weld metal. Fracture surface analysis showed micro-void coalescence as well as quasi-cleavage fracture characteristic of HE. Susceptibility to HE was also observed in the form of secondary longitudinal and internal transverse cracks.

Controlling the detrimental effect of hydrogen on the mechanical behaviour of advanced high strength steels is decisive for their application. Precipitates in steels can be useful in irreversibly trapping the hydrogen atoms, thereby preventing their diffusion to critical regions in the microstructure where they can be most detrimental. In this work, the capability of precipitates of transition metals in limiting the amount of diffusible hydrogen has been examined. A combined ab initio–experimental approach was used to study the hydrogen sorption in two DP800 steel grades with different concentrations of titanium and vanadium using cyclic voltammetryCyclic voltammetry. Under the same charging conditions, diffusible hydrogen concentration was found to be higher in the vanadium grade as compared to the titanium grade. Scanning electron microscope characterisation revealed a more compact layer of oxide on the vanadium grade which contributed to more hydrogen absorption on the surface. Density Functional TheoryDensity functional theory calculations were performed to determine the trapping strength of precipitates of titanium and vanadium. C vacancy in titanium carbide was found to be the strongest hydrogen trap, but the C vacancy formation energy was much lower in vanadium carbide. At finite temperatures, however, both precipitates are experimentally known to be off-stoichiometric. Our DFT-based finding of the titanium grade being irreversible hydrogen trap is thus in agreement with the experimental results.

Stress corrosion crackingStress corrosion cracking (SCC) can adversely affect the life of any engineering component. The study of high entropy alloysHigh entropy alloy (HEA) shows excellent mechanical properties but SCC susceptibility is unknown. We have studied SCC behavior of a transformation-induced-plasticity (TRIP) Fe39Mn20Co20Cr15Si5Al1 (at.%) HEA in 3.5 wt% NaCl solution using slow strain-rate tensile testing (SSRT) on smooth tensile specimens along with the electrochemical behavior of the alloy. The microstructural characterization of the alloy was carried out in as-received condition and after corrosionCorrosion test using advanced characterization tools including X-ray photoelectron spectroscopy. The polarization test of the alloy done in 3.5 wt% NaCl solution revealed corrosion current density as 8.05 × 10−8 A/cm2, markedly lower than the 304 stainless steel (76 × 10−8 A/cm2). The pitting potential of the alloy was 0.089 V. The SSRT result shows a decrease in the elongation and ultimate tensile strength. Further, experiments are in-progress to understand mechanistic origin of decrease in ductility of the alloy.

Process-induced microstructures have a high impact on the fatigue strength of engineering materials. Advanced materials testing builds the base for the design and manufacturing of reliable, high-performance products for various technical applications. Combining modern analytical and intermittent testing strategies with applied enhanced measurement techniques, i.e., physical instrumentation of testing specimens during loading, allows the characterization of process-structure-property relationships in various fatigue damage stages. Further, in situ mechanical testing in analytical devices like micro-computed tomography (µ-CT) enables the immediate correlation of material’s physical reactions with the applied loading conditions. The focus of the presented studies. Using the proposed technique, the characterization of fatigue damage evolution and progression before failure depending on environmental as well as material specific microstructural characteristics is carried out. Investigations on additively manufactured Al alloys revealed the interaction between porosity and microstructure under very high-cycle fatigue (VHCF) loading conditions. Measurement-based fatigue damage tracking during testing of SLM aluminum alloys revealed the interaction between porosity and microstructure under loading in the very high-cycle fatigue (VHCF) regime. The grain boundary strengthening of the microstructure increased VHCF strength by 33%.

The physical and mathematical model of molten converter slagMolten converter slag particle has been established in this paper. The laws of solidification and heat transferSolidification and heat transfer of molten converter slagMolten converter slag particles with the diameter of 2 mm in the process of air quenching granulationAir quenching granulation at different air velocity have been simulated by FLUENT, which the conclusion is as follows: the transformation order of molten converter slagMolten converter slag particles is upwind point → upper point and lower point → leeward point → center point. When the air velocity is 200 m/s and 1 m/s, the time of temperature maintaining phase transformation at the center point is about 0.5 s and 1 s, respectively. Under the conditions of forced cooling and natural cooling, the maximum value of internal temperature difference of converter slag particles is reached after 0.5 s and 2 s, respectively. When v = 200 m/s and v = 1 m/s, the internal maximum temperature differences of converter slag particles were 645 K and 162 K, respectively. Moreover, the maximum internal temperature point is deviated to the right with different cooling conditions. When the air velocity was 200 m/s and 1 m/s, the starting solidification time was 0.05 s and 0.35 s, respectively, and it severally took 0.55 s and 1.80 s to complete the solidification.

Implantable neural interfaces (INI) have gained significant interest since the 1970s. However, the materials currently utilized for neural interfaces suffer from limitations such as degradation, induce a foreign body response, and experience a loss of target neurons in close proximity. Therefore, the development of new implantable device materials for biomedical applications continues to be an important direction of research and development. Carbon-based nanomaterials are promising candidates and also interesting since carbon has many allotropes with different structures and properties, many of which have also been developed for biomedical devices. Moreover, many carbon allotropes have excellent electrical conductivity and mechanical properties. In this framework, the biocompatibility of graphene, carbon nanotubes, and pyrolyzed-photoresist filmsPyrolyzed-photoresist film, which are three very promising carbon-based nanomaterialsCarbon-based nanomaterials (CBN), will be discussed. The neural probe fabricated solely using amorphous silicon carbide as support and pyrolyzed photoresist film (PPF) will be presented as this system represents a highly robust, thin, and flexible neural interface using well-known neurocompatible materials.

After a brief review on the ability of continuum gradient elasticityGradient Elasticity (GradEla) to eliminate singularities fromParisis, K. dislocation lines and crack tips, we present an extension to its fractional counterpart byAifantis, E. C. replacing the classical Laplacian in the gradient-enhanced Hooke’s Law by a fractional one. Then, a discussion on implications of fractional gradient elasticityGradient Elasticity to eliminate stress/strain singularities from a screw dislocation is given, followed by the derivation of the fundamental solution of the governing fractional Helmholtz equation, for addressing more general problems. Finally, an elaboration is provided on using these ideas to revisit interatomic potentialsInteratomic Potentials used in materials science simulations.

Fe–Al alloys have been synthesized directly from Fe2O3–Al2O3 powder by electro-deoxidation in the CaCl2–NaCl molten salt at 800 °C. The thermodynamic decomposition voltages of Fe2O3, Al2O3 and compounds in molten salt to their corresponding metal in 800 °C have been analyzed. Constant voltage electrolysisConstant voltage electrolysis has been utilized to investigate the formation process of Fe–Al AlloysFe–Al Alloys. The results indicated that Fe2O3 is decomposed into Fe earlier. It is found that with the first reduction product Fe, the later reduction product Al will immediately form Fe3Al and FeAl which are more refractory, avoiding the loss of Al due to its low melting point thereby.

Liquid bipolar electrodes (LBE) were proposed for the extraction of noble metals from spent catalystsSpent catalysts by the electrometallurgical method with the production of aluminium and oxygen. The two-sectioned electrolysiselectrolysis cell divided by the LBE for the one-step extraction was designed. The first section acts as the aluminium reduction cell; the second one plays the role of the aluminium refinery cell. The noble metals are collected in the LBE, while the carrier (Al2O3) is decomposed to oxygen and aluminium which is transferred through the second section to be collected in the cathode. The effect of the spent catalystsSpent catalysts content in the melt on the electrode processes and carrier dissolutionDissolution kinetics was studied for molten fluoride systems at 800 °C. The dissolutionDissolution rate lays in the range from 0.0123 to 0.0291 g kg−1 s−1. The extraction of Pt to the LBE reached more than 99%. This method can be applied for the treatment of catalyst based on γ-Al2O3 carrier with a minor content of other oxides (SiO2, Fe2O3, MgO, TiO2, CeO2).

Nimonic 115 is a Ni-based superalloy that contains major alloying elements such as Cr, Co, and Mo. The alloy is used in the manufacturing of turbine blades for aerospace engines. The blades should have high fatigue strength and creep resistance at elevated temperature along with excellent wear and oxidation resistance properties. The presence of γ′ phase with carbide precipitates in the γ phase matrix leads to high strength of Nimonic 115 even at high temperature. The product obtained either casting or powder metallurgy route needs to be thermo-mechanically processed to obtain the improved mechanical properties. Nimonic 115 has a very narrow working range with respect to temperature and strain rate. The reason may be due to the high phase stability of γ′ phase at elevated temperature. During open die forging, Nimonic 115 is prone to surface defect, due to high local flow stress. In the present research work, the effect of heat transfer on deformation due to the transfer of billet from furnace to the forging setup has been examined. The combined effect of reduction and strain rate on the deformation has also been studied. Based on the simulationSimulation results using DEFORM 3D software, the optimum forging conditions have been estimated.

Alloy 709 is a 20Cr-25Ni advanced austenitic stainless steel developed as an improvement over the existing advanced austenitic stainless steels. The alloy’s high Ni content provides increased austenite stability, while its high Cr content improves its corrosion resistance at extreme environments of nuclear structures. In this study, in-situ scanning electron microscope (SEM)In-situ SEM Characterization tensile, creep and creep-fatigue tests at various temperatures from room temperature to 1000 °C will be reported. Electron backscatter diffraction (EBSD) and energy dispersive X-ray spectrometry (EDS) were used to observe the microstructural evolution and phase change during the in-situ heating and loading at different temperatures and strain rates and identify the dominant deformation mechanisms in each environmental condition.

CreepCreep ruptureRupture is currently a major concern forSanders, John W. next-generation nuclear reactor components, and many commonly usedJamshidi, Negar lifetime estimates are based on how quickly intergranular voids grow. Void growthVoid growth is caused by three processes: diffusionDiffusion alongJamshidi, Niloofar the void surface, diffusionDiffusion along the grain boundaryGrain boundary, and creepCreep of the surrounding grains. Previous modeling efforts have only considered two of these three processesDadfarnia, Mohsen at a time. Here we present finite element simulations of void growthVoid growth under the influenceSubramanian, Sankara of all three mechanisms simultaneously. To our knowledge, these are the first such simulations to beStubbins, James reported in the literature. Based on our simulations, we develop quantitative criteria for quasi-equilibrium and crack-like void growthVoid growth and compare them to previous results. Furthermore, we find that void growthVoid growth is highly accelerated during the primary creepCreep regime. Our results promise to aid in the development of microstructure-sensitive material strength models for next-generation nuclear reactor components.

The usage of environmentally friendly materials based on sustainable resources is nowadays more important than ever, especially in technical applications. CottonidCottonid is based 100% on celluloseCellulose, therefore sutainable and due to its excellent properties a promising alternative material in terms of eco-friendliness. Within this study, the deformation and damage behavior of two Cottonid variants, an industrial standard as well as the structurally optimized variant M60Z50, is characterized for the first time using innovative in situ testingIn situ testing techniques. Quasi-static tensile tests were comparatively performed in a scanning electron microscopeScanning electron microscope as well as a microfocus computer tomographMicrofocus computer tomograph, and the development of defects present in the initial condition of the materials were investigated on surface and in volume. In general, in the elastic region, no visible damage initiation on the surface and a decrease of overall void volume within the gauge length could be detected for CottonidCottonid. When reaching the yield strength, cracks initiate on the surface at critical areas, like pores and microcracks, which propagate and assemble until total loss of structural integrity. Further, in the plastic region, an increase in void volume could be shown in the gauge length until final failure. Compared to an industrial standard, M60Z50 exhibits a clearly lower percentage in overall void volume and shows increased mechanical properties, like yield strength and ultimate tensile strength. The structural optimization of M60Z50 seems to result in a more sufficient bonding of the paper layers during the manufacturing process, which improves the deformation and damage behavior under quasi-static loadingQuasi-static loading.

The increased use of composites demands the development of repair processes that can guarantee lasting strength restoration so as to minimize the frequency of expensive downtime. Weak bondsWeak Bonds are a concern for ensuring the structural integrity of a repair and although epoxyEpoxy resins are continuously being developed to have higher strengths than their predecessors, factors such as contaminationContamination levels in the repair bond may result in poor adherence and inhibit overall bond strength. This research compares the response of virgin epoxy plates to short duration acoustic excitation with that of epoxy with varied levels of contamination (0.5, 1 and 10%). Acoustic events were simulated at multiple distances from a high-fidelity displacement sensor, using the Hsu-NielsenHsu-Nielsen technique, and the experimental signals were then assessed in the time–frequencyTime-frequency domain, using the waveletWavelets transform. Results were then compared with previous research on unidirectional carbon fiber laminates with a single contaminant in between plies.

With the development and popularization of material genome engineering, the application of high-throughputHigh-Throughput (HT), experimental technology in metal materialsMetal materials research has attracted more and more attention due to its high efficiency and systematization. This paper briefly introduces the experimental process of high-throughput (HT) technology and its application in metal materials research, especially the application of in-situ metal analysis technology in high-throughputHigh-Throughput (HT), metal materials research, and looks forward to the application of high-throughput (HT) technology in metal materials research.

TemperingTempering kineticsKinetics of the martensite was determined using the Johnson–Mehl–Avrami model in a Cr–Mo–V alloyed medium-carbon steel by dilatometry. Tempering temperatures were determined by non-isothermal analysis at constant heating rate. From these temperatures, isothermal tempering was carried out. The reaction stages were associated with the transformation of retained austenite in bainitic ferrite and cementite, and the conversion of transition carbides into cementite. For the third stage, through dilatometric analysis and the normalization relation, the grade of reaction was calculated and compared with the estimated with JMA model. Finally, this stage was related with the kinetic tempering parameters reported in the literature.

A medium-carbon steel alloyed with vanadium was analyzed by differential dilatometryDilatometry, microhardness and nanoindentationNanoindentation to characterize the fourth temperingTempering stage or secondary hardeningSecondary hardening zone. From isochronal heating paths at different tempering temperatures, the secondary hardeningSecondary hardening zone preceding the martensite decomposition initiation temperature was delimited. A progressive increase in microhardness was observed proportional to continuous tempering temperature increase with respect to start temperature of fourth tempering stage at the lowest heating rate. This increase was related to secondary hardeningSecondary hardening zone by alloy carbides precipitation. Likewise, isothermal tempering was carried out at the start of the fourth temperingTempering stage to verify secondary hardeningSecondary hardening. After the thermal cycles, nanoindentationNanoindentation tests were performed to determine the nanohardness and prove the precipitates presence by scanning probe microscopy. A decrease in the nanohardness of the steel was observed, as well as different size and distribution precipitates depending on the heating rate.

We consider the contact between a sliding wedge/tool and a metal surface prototypical of material removal and deformation processing operations such as forming, cutting, and wear. We show how heat generated at the contact is partitioned into each of the bodies involved: tool, workpiece, removed chip, and surrounding fluid (if any). By performing thermal analysis and heat partition via temperature matching on global and local scales, we show how temperature fields in all four bodies can be easily calculated. The analysis framework involves a heat source moving over a body (Jaeger) and energy partition at the contact into tool, workpiece, fluid, and chip/wear particle (Blok). We present temperature solutions for two cases—incremental forming and grinding—while providing a simple method for solving the thermal problem in other deformation processing applications.

The use of zinc kiln slagZinc kiln slag to prepare Fe-FeAl2O4 cermetFe-FeAl2O4 cermet can realize the recycling of zinc kiln slagZinc kiln slag and promote sustainable development. The thermodynamic behavior was analyzed by XRD, XRF and using FactSage. The results showed that reaction temperature was higher than 710 °C, 7% of C contained in the zinc kiln slagZinc kiln slag can reduce the iron oxide to Fe, and the reduced Fe3O4 and FeO could be reacted with Al2O3 to synthesize FeAl2O4. Complex oxide ores presented in zinc kiln slagZinc kiln slag were advantageous to the preparation of Fe-FeAl2O4 cermetFe-FeAl2O4 cermet. The thermodynamic conditions for preparing Fe-FeAl2O4 cermetFe-FeAl2O4 cermet from zinc kiln slagZinc kiln slag are feasible.

Tailor-designed structure is an essential method to improve energy density capacity retention and energy density of lithium-ionLithium ion batteries batteries. Herein, we designed and synthesized lithium iron phosphateLithium iron phosphate (LiFePO4) with ellipsoidal, hierarchical, and nanosheets morphologies by a solvothermalSolvothermal using phytic acid as phosphorus source. The influence of mole ratio on the morphologies and electrochemical performances were studied. The results illustrated that phytic acidPhytic acid dosage plays a vital role in the tunable morphology syntheses process. Additional, electrochemical measurement confirms that hierarchical LiFePO4 exhibits higher initial discharge capacity (162.09 mAh g−1, 0.1C), more excellent high-rate discharge capability (114.13 mAh g−1, 10C), and better cycle stability (97.2% at 1C after 150 cycles). This satisfactory electrochemical performance could be ascribed to the moderate size and fast ion transport kinetics, which caused by the changing of thermodynamics and kinetics in synthesis process.

Recent advances in 3D printed passive sensorsPassive sensors have opened up new markets in a variety of applications. In order to function, passive sensors do not need any outside power and directly create an output response. These sensors either measure pressure or humidity or temperature or smoke or gases such as ammonia, SO2, CO, and CO2. Advanced 3D filaments/materials are enabling industry to design and manufacture reliable, accurate, and cost-effective sensors rapidly to address the requirements of food and drug industry, monitoring the environment, and biomedical, renewable energy, soft robotics-related applications. The paper will highlight improvements in the manufacture of these sensors and present various case studies. A summary of the market shares of 3D printed sensors will be presented.

Of late, printed electronicsPrinted Electronics continues to experience an increased demand due to enhanced use of flexible electronics, RFID devices, gas sensors, antennas, and intelligent food packaging devices. Due to this demand, the use of inkjet printers and conductive inksConductive ink, with desirable properties, is on the rise. Conductive nanomaterials, such as metal nanoparticles and nanowires, carbon nanotubes, and graphene, are promising building blocks for synthesizing conductive inksConductive ink for printed electronicsPrinted Electronics. In order to develop printing devices that are optimized for flexible electronics, numerical studies on the ink flows and the associated rheological properties are crucial. Therefore, it is critical to provide accurate conductive inkConductive ink properties for reliable numerical results. However, it is difficult to find such data in the literature since conductive inksConductive ink for printed electronicsPrinted Electronics contain precious metal nanoparticles and they are not only non-Newtonian but expensive. To address this challenge, this paper aims to utilize common viscosityViscosity–shear rateShear rate models such as the power law modelPower Law model to study rheological properties such as viscosityViscosity, shear rateShear rate, and shear stressShear stress of conductive inksConductive ink. Notably, conductive inksConductive ink made from metal nanoparticles such as silver, copper, gold, nickel, and aluminum are considered in this study. The results obtained from this model have been compared with experimental data. To further understand the effects of temperatureTemperature and viscosityViscosity on synthesized ink, the viscosityViscosity–temperatureTemperature relationship of the conductive inkConductive ink is also modeled using Arrhenius’s law and compared with experimental data. The benefits of using this model for performing numerical simulations of desirable rheological properties of conductive inksConductive ink for printed electronicsPrinted Electronics are discussed.

Chromium doped ZnSeZnSe nanocrystalsNanocrystals were grown at low temperature using zinc acetate and sodium selenite. A capping agent was used to avoid agglomeration of particles. It was observed that the addition of the capping agent before or after chemical synthesis of ZnSe played a very important role in controlling the size of nanoparticles and to avoid agglomeration. Size of nanoparticles of ZnSe was as small as 10 nm for both doped and undoped material. In a few cases, in spite of preventative measures, clustering of particles produced large agglomerates at room temperature. Cr-ZnSe nano particles showed fluorescence at different wavelengths compared to Cr-doped bulk crystalsCrystal. Cr-doped nanocrystalsNanocrystals showed higher bandgap than PVT grown bulk Cr-ZnSe crystals. The fluorescence intensity for Cr-ZnSe nanoparticles was significantly higher compared to undoped ZnSeZnSe nanoparticles.

Printed circuit boards, collected from Bangladesh, were melted to determine the proportion of metal, ceramic and volatile components. The concentration and amount of valuable elements in the e-wasteE-waste were calculated from the analysis of the metal and ceramic phases. This information was used to design a simple three-stage process to recover the valuable components. The stages included smelting, electrorefining of a copper rich anode and melting of anode slimes and reduction of a tin rich slag. In this process, copper would be recovered as a high purity cathode, silver and gold recovered as a precious metal bullion from the processed anode slimes and tin recovered from the reduction of tin rich slag. A flowsheet simulation of this process was used to estimate the size of unit operations and process streams. Capital costsCapital costs of the process situated in Bangladesh were estimated based on the equipment required and included capital on-costs. Operating costsOperating costs were estimated from power, labour and consumables required as well as operating factors such as maintenance and administration. Cash inputs to the process were estimated from the value of product streams. The preliminary financial viability of the process was estimated, and net present value and internal rate of return are determined.

A numerical model was developed to simulate the current density distribution and secondary resistances for the aluminum electrorefining process from the room temperatureIonic liquid ionic liquid (RTIL) consisting of 1-butyl-3-methylimidazolium chloride and aluminum chloride with the molar ratio of 2:1 (AlCl3: BMIC). The materials and geometry were created based on the experimental parameters. The current density distribution was calculated via simulation. The effects of applied voltage, temperature, composition of the electrolyte, and the surface roughness of cathode on the secondary resistances were investigated in this research. It was found that the summation of contact and charge transfer resistance decreases with increasing the potential and the temperature as well as decreasing the surface roughness.

The conductivityConductivity of the mixture of 1-butyl-3-methylimidazolium chloride (BMIC) ionic liquid with aluminum chloride (AlCl3) and titanium chloride (TiCl4) are systematically investigated over a range of temperature (70–110 °C) using the electrochemical impedance spectroscopy (EIS) method. The molar ratios of the components are changed to study the effect of molar ratio on the conductivity. The conductivityConductivity data are plotted against temperature to check whether it obeys the Arrhenius law. The activation energy and the density are calculated. The conductivityConductivity of the solution increases with increasing temperature for every composition. For varying molar ratio, conductivity increases with increasing TiCl4 content up to a certain composition then starts to decrease for each temperature. At room temperature, density of the solution increases with increasing TiCl4 content in the solution.

Aligning with the global goal of conserving mineral resources, it becomes necessary to evaluate the potential ceramic applicationCeramic application of mullite rich tailingsCopper tailings from density separated copper smelter dustCopper smelter dust (CSD). The aim was achieved by determining the physico-chemical analyses and mechanical property of mullite rich tailingsCopper tailings for size fractions, chemical species, and hardness property, respectively. Screening test, XRF analysis, and Vickers hardness testHardness test of spark plasma sintered samples at 700 °C, 800 °C, and 900 °C were methods used. Results, showed 309.475 g of total mass (400.078 g) passed 53 µm sieve. Chemical analysis showed significant presence of silica (36.6 wt.%) and alumina (28.4 wt.%) in tailings. While, the micro-hardness results showed tailings sintered at 900 °C had the highest hardness value of 23.64 HV; presupposing increased sintering temperature will result in increased micro-hardness. In conclusion, results show copper tailingsCopper tailings can be used for high temperature ceramic applicationsCeramic application; thus, making the proposed density separationDensity separation-hydrometallurgical-based approach for treatment of CSDCopper smelter dust, a sustainable technology, with high chances of zero waste production.

Electrodeposition of aluminum was conducted on three types of ionic liquidsIonic liquids (ILs); EMIC, BMIC and HMIC with AlCl3. The molar ratio of IL:AlCl3 = 1:2 was determined to be optimum for all three ILs. Over 170 A/m2 current densityCurrent density with more than 85% current efficiency was obtained for EMIC system. Similarly, for BMIC, over 300 A/m2 current densityCurrent density was found with more than 85% current efficiency, and for HMIC, more than 250 A/m2 of current densityCurrent density with over 85% current efficiency was obtained. Based on the lab-scale experimental findings, scale-up experiments were carried out for BMIC:AlCl3 = 1:2 molar ratio. Significant increase in current densityCurrent density was observed when higher potentialsPotential were applied. More than 220 A/m2 of current densityCurrent density was observed for the scale-up system. Additionally, shorter distance between anode and cathode (~1 cm) and higher stirring rate (120 rpm) produced higher current densitiesCurrent density. The outcome of this work would facilitate the scale-up studies for the electrochemical separation of aluminum from mixed scrap.

Nickel slagNickel slag can be recycled as one of excellent secondary sources due to valuable iron resource. A static model of recycling nickel slagNickel slag by aluminum drossAluminum dross was established based on material balance and non-isothermal thermodynamic calculations. Discussions had been carried out under different basicities of the modified slags and the reduction degree of ‘FeO,’ and the results showed that the dosage of nickel slagNickel slag, aluminum dross,Aluminum dross and modifier is 55.60%, 28.82%, and 15.58%, respectively, at the basicity of modified slag of 1.0. The non-isothermal thermodynamic modelNon-isothermal thermodynamic model indicated that an increment of slag temperature from 114.3 to 430.2 K could be obtained with the reduction process, which not only signified the superiority of aluminothermy, but also laid a foundation for the industrial practice.

CeriumCerium recovery from a secondary waste stream generated after the extraction of Pt-group metals from spent catalytic converter has been investigated. Different mineral acids alone used as lixiviant could leach only 33% cerium; however, HF added acid mixture showed an increased leaching up to 96%. The determined value of activation energy 31.8 kJ/mol revealed that leaching progressed via diffusion-controlled mechanism. Subsequently, ceriumCerium from leach liquor was extracted using 4 tri-alkyl phosphine oxides in kerosene, which indicated the formation of extracted species to be $$\left[ {{\text{Ce}}({\text{SO}}_{4} )_{2} .2L.{\text{HSO}}_{4}^{ - } } \right]_{{{\text{org}}}}$$ Ce ( SO 4 ) 2 . 2 L . HSO 4 - org . The loaded organic was quantitatively stripped back into the H2SO4 solution by adding an H2O2 dosage as a reducing agent. Thus, obtained Ce-bearing stripped solution was treated with oxalic acid to precipitate high-purity Ce2(C2O4)3. The process is simple and potentially dealt to recycle the critical metal values which remained less attractive until now.

To increase the yield by decreasing the amount of residual molten steel in tundish, the vortex flow characteristicsVortex flow characteristics of the molten steel was investigated in a practical three-strand bloom tundishThree-strand tundish at the end of casting using physical and numerical simulationPhysical and numerical simulation. The results showed that the vortex was strongly dependent to the asymmetric distribution of molten steel and the casting speed, so the vortex flow first occurred at strands 1 and 3, and the height of vortex formation was decreased by 25% while the casting speed was decreased from 0.65 to 0.48 m/min for the bloom with section size of 360 mm × 300 mm. Furthermore, the use of a square inhibiting baffleInhibiting baffle could disturb the upper fluid flow to decrease the height of vortex development by 23% at the casting speed of 0.48 m/min. Therefore, the installation of square inhibiting baffleInhibiting baffle is recommended, and the casting should be operated at lower casting speed.

Metal additive manufacturing (AM) is an evolving technology, and the supply of quality feedstock material needs to follow suit. Closed-coupled optimized-pressure gas atomizationGas atomization (CCOPGA) promisesHernandez, F. narrow size distribution, spherical powder, and optimized use of gas. However, pour-tube melt solidificationSolidification isDeaton, E. an obstacle to enabling a wider alloy palate. Many solutions involve adding melt superheat, but do notProst, T. account for all cooling influences. While the Joule-Thomson effect and forced convectionConvection promotes high cooling rates for the powder, excessive heat loss can leadAnderson, I. E. to freeze-off. Therefore, optimizing the melt delivery geometry is needed to reducefreeze-off and down time. Analytical and numerical models are employed to studythe heat transfer process between the pour tube and the surroundings for CCOPGA of both Ni and Ca melts. The effects of normalized length, radius, and thermal diffusivity are considered. Work supported by USDOE-EERE-AMO and USDOE-OE through Ames Laboratory Contract No. DE-AC02-07CH11358.