TMS 2019 148th Annual Meeting & Exhibition Supplemental Proceedings

Based on experimental observation, ab initio molecular dynamicsAb initio molecular dynamics was used to investigate the dissolutionDissolution of interfacial iron oxides in hot compressive bondingHot compressive bonding (HCB). The surface analysis indicated that there was reoxidation at the unclosed iron surface during the sample heating in HCB. The bonding of pre-oxidized iron was designed to verify the dissolutionDissolution of iron oxides into matrix. Two models were proposed to understand the dissolution behaviorDissolution behavior with dynamic simulations. Model I was applied to the case with bonding interface between oxides and matrix,in which periodical interface structure of Fe3O4/BCC-Fe was constructed. The dissolutionDissolution of Fe3O4 contained the initial structural dissociation and the diffusion of free oxygen and iron atoms into matrix. It was found that the diffusivity of iron was higher than oxygen. Model II with embedded structure of oxide cluster was proposed to understand the initial dissolutionDissolution of iron oxide particles in the matrix. The mean square displacement (MSD) results suggested that the local strain may promote the process by increasing the mobility of oxygen. And the Bader charge analysisCharge analysis implied that the electron contribution of iron matrix and its transfer to the dissociated atoms plays a key role in the initial dissolutionDissolution of interfacial iron oxides.

With the increasing shortage of iron concentrate powder resources, the optimization of blast furnaceFurnace charge structure by using the fluxed pelletsFluxed pellets has become an important method to reduce the cost of iron making in iron and steelSteel enterprises. To solve some problems, such as bonding, ringing, and so on; the effect of MgOMgO on the properties of pellets has been studied. The results show that with the increase of MgOMgO , the compressive strengthStrength of green pellets increased, while the dropping strengthStrength of green pellets decreased. The decrepitation temperature increased at first and then decreased, and the bond rate decreased. The performance of the pellets improved. The hematite content decreased and the magnesiumMagnesium ferrite content increased in main crystal phase of the pellets, which was mainly linked by crystal bond.

Gas-stirring has been an important method for secondary refining process of steelSteel . The interaction of gas bubbles with the interface of liquid steelSteel and molten slagSlag has been simulated in this study. The model is based on the phase-fieldPhase-field method for three-phase flow of steelSteel -slag Slag -gas. The micro-flow with a sharp interfaceSharp interface tracking among the phases of an argon bubble floating in steelSteel and motion across the steelSteel -slag Slag interface is obtained and discussed. By the model, it is found that there is a critical size for bubbles to pass the interface. Bubbles with a smaller size than the critical value will not pass the interface and settle under the slagSlag phase when they contact with the interface for the first time. This result different from the past knows that the bubble will 100% pass the interface. A water model was set to invalidate the numerical model and the experiment result shows agreement with the numerical model.

Spent die cleaning solution from AluminiumAluminium extrusion industry is a harmful waste which affects the environment and the sewage pipes due to the presence of caustic sodium hydroxide and sodium aluminate solutions. An experiment carried out to study the effect of pH and temperature in the conversion of that waste to useful materials used in other industries by carbonation of spent die cleaning solution which has known content of free OH− % and CO 3 −2 %. The pH and Temperature are controlled and measured by HANNA INSTRUMENTS.HI 9219 during the carbonation process time which takes 2 h with CO2 gas pressurePressure less than 0.1 psi which induces the best economic benefits when this research applied industrially. It is observed that the pH increases from ambient temperature 25.6–45.3 °C and then decreases to 41.4 °C, then starts to increase again till the end of the 2 h time to reach 42.2 °C. During the carbonation process it is observed the formation of white flakes suspended in the solution, the solution then settled for 24 h where the white precipitate then formed, dried and examined by XRD instrument, ICP-VISTA MPX, LECO CS-244, FT/IR 4100 JASCO and JEOL JSM-5500 LV Scanning Electron Microscope (JEOL, Japan), to detect the type of the precipitate, which is Al(OH)3 in three different forms fresh forming Gibbsite, Aging Gibbsite and Bayerite, which are useful materials in various industries.

A two-dimensional finite element modelFinite element model has been established based on thermal–mechanical coupled calculation for the determination of soft reductionSoft reduction amount by convex roll during bloom continuous castingContinuous casting . The shrinkage of the mushy zone is then calculated based on mass conservation during solidificationSolidification . The total shrinkage area is about 75 mm2 for the 180 × 240 mm2 bloom with a casting speed of about 1.25 m min−1. The reduction efficiency of the convex roll is calculated on basis of the visco-elastic-plastic deformation behavior of mushy zone. It decreases linearly from 31.7 to 4.7% when the center solid fraction of the reduction location increases from 0.3 to 0.6. The maximum stress is observed on the bloom surface where the strand contacts to the chamfer of the convex roll, while the maximum plastic strain appears in the inner-arc mushy zone. The total soft reductionSoft reduction amount suggested by the present model is 6.06 mm. It is noticed that the center segregationSegregation and “V” segregationSegregation have been improved remarkably by soft reductionSoft reduction with convex rolls.

An experimental physical modelPhysical model was set up on the base of the fluidized furnaceFurnace of a factory. The influence of top gas flow rate and position on gas–solid flow distribution characteristicsGas–solid flow distribution characteristics were analyzed by the experimental comparison in bed. The results were shown that the gas–solid mixture was more homogenous distribution and had less effects from the top gas when the ratio of bed height to diameter was 1.58, the apparent gas velocity was 0.13–0.18 m/s and the continuous charging speed was 360 kg/h. The depth of the top jet had a great effect on the gas–solid flow in the expansion part of a babble fluidized bedA babble fluidized bed . The elutriation and sticking of particles on the wall were decreased with the depth of the position of the jet increasing.

Geopolymers have been synthesized using metakaolinMetakaolin produced from kaolinites extracted from several regional soils. To obtain higher strengthStrength and stiffness, the geopolymerGeopolymer matrix is reinforced with fiber. In addition, synthetic, natural particles and fibers have been used to enhance durability, thermal properties and shrinkage ratio of the lighter geopolymerGeopolymer composites. Owing to the unavailability of a standard for processing and testing the geopolymerGeopolymer composites, different procedures currently being used are making data comparison very difficult. The promising market of geopolymerGeopolymer and ceramics matrix composites for the sustainable construction industry would benefit from a uniform standard for laboratory processing and testing. This would contribute to the creation of a large and reliable data bank and facilitate the manufacture and certification of geopolymeric-Polymeric and/or ceramic-based sustainable construction materials. This study developed palm oil fiber reinforced kaolin matrix composites for building bricks. The effects of chemical treatment on the mechanical propertiesMechanical properties of the oil palm fiber reinforced ceramic matrix composites were examined. The water absorption rate of treated developed samples was lower in comparison with untreated samples, and hence the chemical treatment enhances the mechanical propertiesMechanical properties of the material.

A two-dimensional finite element modelFinite element model based on elastic-visco-plastic constitutive laws has been established to investigate the effect of roll surface profileRoll surface profile on thermal-mechanical behaviorThermal-mechanical behavior of steelSteel in the convex roll soft reductionConvex roll soft reduction (CRSR) process during bloom continuous castingContinuous casting . The reduction efficiency of convex rolls under different conditions and the probability of internal crack in the bloom has been discussed in this study. It is noticed that the reduction efficiency of the narrow convex roll is larger than that of the wide convex roll with the same reduction force or reduction amount. Besides, with the increasing solid fraction of the bloom center in the reduction zone, the reduction efficiency of the convex roll decreases, while the needed reduction force increases. Furthermore, the narrow convex roll is more sensitive than the wide to the formation of internal crack under the same reduction amount, especially in the cases where the solid fraction bloom center is low.

The traditional stainless steelStainless steel smeltingSmelting process used O2 blowing to achieve decarbonization and chromium conversationDecarbonization and chromium conservation . The increase of steelSteel production is accompanied with an increase of CO2 emissions while CO2 has weak oxidation at high temperatures. The feasibility of using CO2 for stainless steelStainless steel smeltingSmelting in AOD furnaces and the effect of decarbonization and chromium conservationDecarbonization and chromium conservation were verified by thermodynamic calculations in this paper. The theoretical calculations show that CO2 can completely replace O2 blowing which is convenient to control the progress of the reaction in the bath. The CO2 injection ratio should be controlled between 20 and 40%. High proportion of CO2 injection will not only make the molten pool temperature too low, but also extend the smeltingSmelting cycle. In addition, the higher the CO2 jet flow, the higher the decarbonization rate in the middle and late stage of the smeltingSmelting process.

On these days, display industries have rapidly adopted high-performance oxide semiconductors (OS, such as amorphous InGaZnO semiconductor) as an active layer in active matrix organic light-emitting diodes (OLEDs), liquid crystal display (LCD), and flexible active matrix device applicationsApplications . In this talk, I will present the recent progress of OS materials and the associated device application. Unlike commercial sputtering method, atomic layer depositionAtomic Layer Deposition (ALD) can make an opportunity to enhance not only device performances but also flexible properties. First, I will show various oxide semiconductors deposited by ALD and compare with their semiconductor properties and device performances. Also, multicomponentMulticomponent oxide semiconductors (such as ZnSnO, InZnO, InGaO, InZnSnO, InGanZnO, etc.), deposited by super cycle ALD methods, will be discussed regarding process issues vs. material properties. Then, I will show the effect of various ALD-based gate insulators on oxide semiconductorOxide Semiconductor thin film transistors (TFTs). The ALD-based gate insulators will be important roles to consider panel and circuit designs. The mobility and stability of the devices will be discussed in terms of gate insulators. The flexible oxide semiconductorOxide Semiconductor thin film transistors will be presented via ALD methods, and the device may be evaluated by mechanical stresses such as bending radius and mechanical fatigueFatigue . This work will be an important suggestion for ALD-based device applicationsApplications .

HF, CF4, C2F6 and SiF4 are the main fluoride gases evolved in the Hall–Heroult process. However, the major contributor of fluoride is HF. Since these gases are very toxic, they must be adsorbed from the environment. In this research, adsorption of HF, CF4, C2F6 and SiF4 in aluminiumAluminium smelter is discussed and compared. Due to the capability of nanotubes in gas adsorption, this study has been conducted to figure out the adsorption of fluoride gases on (8,8) armchair carbon nanotubes (CNTs). Lennard-Jones potential was used for gas–gas and gas–carbon nanotubeCarbon nanotube interactions. In addition, the potential parameters for the carbon–gas and carbon–carbon interactions were obtained from the Lorenz-Berthelot combining rules. The simulationSimulation results showed that this adsorption can be a possible solution for separation of toxic gases from the environment. The proposed method provides a new horizon in the aluminiumAluminium industry.

Gas-insulated switchgearGas-insulated switchgear (GIS) using sulfur hexafluoride (SF6) as insulating medium has been widely utilized in electrical industry. However, SF6 gas will decompose into several components under partial discharge, like SO2, SOF2, and SO2F2. TiO2 TiO2 nanomaterials were reported to have an excellent performance in the gas-sensitive fields. In this paper, we have proposed a new method of online monitoring to detect these products by nitrogen-doped TiO2 TiO2 nanotubes sensor (N–TiO2 TiO2 ) in order to easily evaluate the operating condition of GIS. We first set up the experimental platform for this work, and then separately discussed the gas-sensitive response characteristics of N–TiO2 TiO2 to three by-products. Finally, repeatability of this gas sensor was measured. The results show that the N–TiO2 TiO2 have a good repeatability as a gas sensor. The sensitivity of the N–TiO2 TiO2 to SO2F2 is weakest. Compared to SO2F2, the N–TiO2 TiO2 is more sensitive to both SO2 and SOF2, and better to SO2.

Metals and alloys are widely used in dentistry, medicine and restoration of defected bone as artificial implants or restorative materials. Bone implants are mainly made of metals to be able to withstand mechanical stresses during operation. Stainless steelStainless steel 306L is the most common alloy used in the manufacture of bone implants. The main characteristic of this alloy is to have good mechanical propertiesMechanical properties , but there is always concern about the corrosion resistanceCorrosion Resistance of them in physiological and bioactive solutions. In this study, HardystoniteHardystonite nano-bioceramic was prepared by sol-gelSol-gel method and after surface preparation was applied on 316L steel316L steel at 3 and 5 min time durations and 30 and 50 V voltages using electrophoreticElectrophoretic method. The corrosion resistanceCorrosion Resistance of 316L316L stainless steelStainless steel in ringer solutionRinger solution was measured by potentiodynamic polarization test at constant temperature of 37 °C before and after coatingCoating process which due to very good bioactivity of HardystoniteHardystonite ceramic the corrosion resistanceCorrosion Resistance of 316L steel316L steel has also increased. The surface microstructureMicrostructure of the coated specimens was investigated using a scanning electron microscope (SEM). The composition of phases and elemental characterizationCharacterization of the coatings was determined by X-ray diffraction method. Results show that the obtained coatingCoating on 316L steel316L steel is nearly uniform and has no apparent defect at 50 V and 5 min. The HardystoniteHardystonite coatingCoating has improved the corrosion resistanceCorrosion Resistance of the substrate so that the corrosionCorrosion current density in the coated samples is less than the uncoated ones and the corrosion resistanceCorrosion Resistance of 316L steel316L steel has increased 9 times. The results showed that HardystoniteHardystonite bioceramic coatingCoating applied by electrophoreticElectrophoretic method can improve the corrosion behaviorCorrosion behavior and consequently the biocompatibility of metallic implant in medicine applicationsApplications .

Among fascinating polymer structures, porous and hollowHollow core structures are usually desirable because of their numerous applicationsApplications . Herein, we present hollowHollow core structures of polystyrenePolystyrene (PS) microspheres via a simple one-pot novel synthesis using Sodium dodecyl sulfateSodium dodecyl sulfate (SDS) and Cetyltrimethylammonium bromideCetyltrimethylammonium bromide (CTAB) emulsifiers. The colloidal microspheres are assembled into a non-compact order of colloidal crystal arrays. Microscopic analysis showed that CTAB emulsifier can influence a micelle to act as a soft template for the fabrication of PS particles with inner core hollowHollow interior compared to SDS emulsifier. The optical analysis of the SDS-emulsified PS colloidal crystal films gave wavelengths of 527.011 nm and 642.967 nm that varied from yellow to red colouration as the observation angle changed from 2 to 10 °C, respectively, while CTAB-emulsified PS colloidal crystals showed wavelengths of 556.233 nm and 589.442 nm that corresponds to monochromatic yellow colour that did not change with observation angles. This economic and environment-friendly one-pot procedure can be used to generate a soft-micelle template for the actualization of hollowHollow PS microspheres that may find potential applicationsApplications as catalysts, fillers, coatingCoating materials and drug delivery.

Novel hydrangea-like VS4 VS4 nanomaterials as high-performance electrode materials of supercapacitors were successfully synthesized by hydrothermal method using Na3VO4 · 12H2O2, citric acid and TAA (thioacetamide). The prepared samples were characterized by XRD, SEM and BET, CV (cyclic voltammetry) and GCD (galvanostatic charge and discharge). The results revealed that VS4 VS4 are hollowHollow microspheres with a diameter of ~5 μm and made of nanosheetsNanosheets , the microspheres formed from diffusion growth of solid microspheres. These materials exhibited a tremendous specific capacitance of 533 F/g, at 0.1 A/g in the potential range of −0.9 to 0 V when used as supercapacitor electrodes in a solution of 1 M Na2SO3. The energyEnergy density is as high as 60 Wh/kg, which is much higher than those of many other symmetrical supercapacitors. In addition, the capacity retention of 80% was achieved even after 500 cycles, demonstrating the high performance of vanadium oxide nanomaterials used in supercapacitors.

Based on the high thermal and electrical conductivityElectrical conductivity of grapheneGraphene and the excellent corrosion resistanceCorrosion Resistance of Perfluoroalkoxy (PFA), a novel grapheneGraphene -PFA compositeComposite was proposed to simultaneously meet the demands of heat transferHeat transfer and corrosion resistanceCorrosion Resistance . Ultrasonic dispersionUltrasonic dispersion technology was used to disperse the aggregated graphene in the compositeComposite . GrapheneGraphene -PFA composites with different grapheneGraphene content were prepared by hot pressing and cold-press sintering. We analyzed the thermal decompositionThermal decomposition , compressive strengthStrength , electrothermal propertiesElectrothermal properties . There was no phase change occurred below 300 °C, the grapheneGraphene -PFA composites had a high thermal stability below 300 °C. The compressive propertiesCompressive properties of the compositeComposite prepared by hot pressing were better than cold-press sintering. Increasing the content of grapheneGraphene greatly improved the thermal conductivity and conductivity of the compositeComposite . The uniformity of grapheneGraphene distribution inside the compositeComposite was verified by infrared camera.

Widely Silver nanoparticlesNanoparticles (AgNPs) have been investigated because they exhibit optical, electronic, and chemical properties, based on their size and shape, opening many possibilities with respect to technological applicationsApplications . This study reviews the synthesis of AgNPs using simple polyol method. The AgNPs characterized by using Ultraviolet-Spectroscopy (UV-Vis), Transmission Electron MicroscopyElectron microscopy (TEM)TEM , and X-Ray Diffraction (XRD). AgNPs are synthesized by the chemical reduction of silver nitrate, Ethylene Glycol (EG) and Polyvinylpyrrolidone (PVP). The UV-Vis revealed the formation of silver nanoparticlesNanoparticles by exhibiting absorption maxima at a wavelength of 420 nm. The TEMTEM showed homogeneity of the particle size in the sample, the average size was from 10 to 50 nm. XRD patterns show that the crystal size also ranges from 10 to 50 nm and are in good agreement with the standard values of the fcc of silver.

In order for metallic additive manufacturingAdditive manufacturing (AM) to find application in industrial production environments, methods for quality control need to be developed. Presently, even precisely calibrated process parametersProcess parameters cannot prevent the stochastic occurrence of defects resulting from elements in the AM process which are difficult to control. This study utilizes low framerate (10 Hz) pyrometry to record in situ temperature measurements of the molten pool and surrounding substrate in LENSTM AM. The data is statistically analyzed in search of anomalous behavior which is compared to the actual population of voids and inclusions found using X-ray Computed Tomography. This statistical analysis technique was able to identify volumetric defects as small as 40 μm in diameter as well as inclusions such as powder contamination. This study shows that the thermal analysis parameters can be tuned specifically for detecting different anomalies in the build.

To emulate the refurbishment of service-damaged cast nickelNickel aluminumAluminum bronze (NABNickel Aluminum Bronze (NAB) ) components, a laser-additive repair process using NABNickel Aluminum Bronze (NAB) powder feed was developed. Process parametersProcess parameters were first optimized using Taguchi experimental design based on the lowest dilution ratio criterion. The dilution ratio was obtained from single weld beads deposited on flat substrates. Using the optimum process window developed on the flat substrates, the process parametersProcess parameters were further modified to deposit multiple weld beads in a grooved substrate, which was used to emulate remanufacturing of a service-damaged surface condition. Using the optimum laser-additive repair process developed, sound deposits with no cracks but some micropores at acceptable levels for the application, were successfully manufactured. The microstructureMicrostructure and microindentation hardnessHardness of the deposited specimen were evaluated in the as-deposited condition.

Austempered ductile ironAustempered ductile iron (ADI) with ausferrite structure is now of great interest for its low production cost, good recycling capacity, excellent castability and a wide range of mechanical propertiesMechanical properties . However, for more design flexibility and more use of low-cost potential material as well as for repairing the casting defects in producing ADI, the importance of welding DI which could be later converted to ADI, cannot be overridden. In the present work, coated electrode was first developed for grade I ADI without and with cerium using nano-CeO2 and weld procedure was established as per AWS (D11) using preheat at 300 °C for 1 h followed by post-weld heat treatmentHeat treatment (PWHTAnd post-weld heat treatment (PWHT) ) for 300 °C for 1 h immediate after welding. DI weldments were then austenitized at 900 °C for 2 h holding time followed by austempering at 300 and 350 °C for three different holding times (1.5, 2 and 2.5 h) at each austempering temperature. Results show that both the weld metals responded austempering heat treatmentHeat treatment ; but more refined bainitic ferrite and increase volume percentage of retained austeniteRetained austenite were obtained in Ce containing weld metal compared to without Ce containing weld metal. Though 100% joint efficiency was observed in both the welded joints (with and without Ce), fatigueFatigue strengthStrength and charpy impact toughnessImpact toughness of ADI weld metals enhanced with the addition of Ce.

The formation of different weld defects like porosityPorosity and intermetallicIntermetallic compound (IMCs) in dissimilar electron beam welded (EBWElectron beam welding (EBW) ) joints between DP600 steelSteel to Al-5754 alloy was studied. EBWElectron beam welding (EBW) was performed under three weld conditions i.e. without beam oscillationBeam oscillation and with beam oscillationBeam oscillation at two different beam oscillationBeam oscillation diameters for selecting weld parameters to obtain best quality weld products. X-ray diffraction, scanning electron microscopyElectron microscopy with energyEnergy dispersive spectroscopy (EDS), micro hardnessHardness were performed to characterize pores and IMCs qualitatively. Three-dimensional (3D) X-ray computed tomography (XCTX-ray tomography (XCT) ) was also used to visualize and quantify both the defects and their distribution in 3D space at different regions of the joint such as fusion and heat-affected zone. Sample characterizationCharacterization with different characterizationCharacterization techniques demonstrated that application of beam oscillationBeam oscillation with optimum oscillation diameter (1 mm) produced the best quality joints by decreasing both the defects significantly. It was further confirmed that increasing oscillation diameter beyond its optimum value, deteriorated the weld quality noticeably.

304 stainless steelStainless steel parts of single pass were fabricated by wire and arc additive manufacturingAdditive manufacturing using gas tungsten arc welding (TIG) and ultrasonic micro-forgingUltrasonic micro-forging . The microstructure and microhardnessMicrostructure and microhardness were studied at different powers of ultrasonic micro-forgingUltrasonic micro-forging . The relationship between microhardnessHardness and power of ultrasonic micro-forgingUltrasonic micro-forging was established. It was found that the parts were well formed and no defects such as micro-cracks or pores were observed. Different thermal historiesThermal History resulted in various microstructuresMicrostructure . The microstructureMicrostructure of parts was fined by the treatment of ultrasonic micro-forgingUltrasonic micro-forging . The microhardnessMicrohardness of the parts was also enhanced by the treatment of ultrasonic micro-forgingUltrasonic micro-forging while declined from the top to the bottom of the fabrications. When the power of ultrasonic micro-forgingUltrasonic micro-forging was fixed at 1000 W, the depth of action from ultrasonic micro-forgingUltrasonic micro-forging comes to about 1 mm and the maximum of microhardnessMicrohardness reached to 350 HV0.1.

Microstructural evolution and characterizationCharacterization of interfacial reactions during friction welding of commercially pure titaniumTitanium and 304 stainless steelStainless steel using a Ni interlayer were investigated. A thin interdiffusion solid solution layer and a discontinuous layer of Ti–Ni-type intermetallic compoundsIntermetallic compounds formed adjacent to the titaniumTitanium –nickel Nickel interlayer interface. The weld interface of titanium to interlayer has formed with three types of layers which are consisting of TiNi, TiNi3 and Ti2Ni, intermetallic compounds. The interdiffusion path for the reaction of intermetallic compoundsIntermetallic compounds was established at this interface. Electron probe microscope analysis (EPMA) revealed the formation of Ti–Ni-based intermetallic compoundsIntermetallic compounds and confirmed the absence of Fe–Ti-type brittle intermetallic compoundsIntermetallic compounds . Tensile tests indicated that the failure in the joints occurred by formation and propagation of the crack mostly along the titaniumTitanium –nickelNickel interlayer interface, through the Ti–Ni-type intermetallicIntermetallic layers.

Laser-based additive manufacturingAdditive manufacturing of metals relies on many micro-sized welds to build a part. A simplified, well-studied case of this process is a single scan of the laser across a single layer of powder. However, there is a lack of mechanical propertyMechanical property measurements of the tracks produced in such experiments. Nanoindentation measurements on laser track cross sections of nickelNickel superalloy 625 reveal hardnessHardness differences between the track melt poolMelt Pool and base material as well as variations with laser scan speed. There is a change from ≈5.5 GPa in the track melt poolMelt Pool to ≈4.8 GPa in the base material for laser settings of 195 W and 800 mm s−1. In comparison, the increase in hardnessHardness in the melt poolMelt Pool is not observed for settings of 195 W and 200 mm s−1. It is believed that the difference in thermal histories supported by thermographic measurements causes a difference in the dislocation densityDislocation density in the melt poolMelt Pool . This results in a difference in hardnessHardness between the two tracks. The effects of the local crystal orientation, dendritic spacing, and residual stressResidual stress are considered in the interpretation of results.

This study investigated the effect of laser peening on the surface integritySurface integrity (surface roughnessSurface roughness , microstructure and microhardnessMicrostructure and microhardness ) of 17-4 PH stainless steelStainless steel components which were built through the direct energyEnergy deposition (DED). Additive manufacturingAdditive manufacturing (AM) technique was performed on laser engineered net shaping (LENSLENS ) system. Components were built through the same energyEnergy density of 312.9 J/mm3 and subsequently subjected to laser peening so as to modify the surface of the material. However, one component was peened for three cycles and the other one for six cycles. The current study discovered that the surface roughnessSurface roughness improved by 28% for three cycles of peening and 42% for six cycles of peening. Moreover, it was found that laser peening caused deformation of grains just below the peened surface which consequently resulted in increment of microhardnessMicrohardness .

Nowadays, additive manufacturingAdditive manufacturing (AM) enables research institutions and companies to make a prototype of a complex apparatus in a timely and cost-effective manner. In this study, a cyclone separator is designed and built, using one of AM technologies [i.e., fused deposition modelingModeling (FDM)] for removal of solid contaminants. The FDM-printed cyclone has been integrated and empirically verified on the catalytic fast pyrolysis conversion process for bioproducts (e.g., bio-oil and biochar) production from biomassBiomass feedstocks. The Pyrolysis process is near commercial ready, yet requires further research to address shortcomings (e.g., process yield and product quality) in the major components, such as feed system, reactor, cyclone, and condenser. Lab-scale, three-dimensional (3D) printed prototypes can, in turn, accelerate the evaluation process before developing the final conversion process components. AM is one of the promising approaches for prototypingPrototyping a complicated apparatus in bioenergy productionBioenergy Production process.

In selective laser melting (SLM), temperature gradients and cooling rates are extremely large in comparison to the ordinary directional solidification process. Therefore, the standard analytical methods are not able to predict the dependency of the dendrite arm spacing on the process parameters correctly. In the current research, we use a quantitative multicomponent phase-field model to investigate the arm spacing during the SLM process taking into account the dependency of the tip undercooling on the solidification velocity. It is found that the precision of the phase-field method can be estimated by a stability parameter which is defined as a ratio of the numerical resolution to the solidification velocity and should be chosen larger than a critical value. We show that our developed results are in good agreement with the theoretically obtained ones based on Kurz–Fisher method. We investigate the microstructure evolution and component distribution in Fe–Mn–Al–C solidified alloy during SLM process. The arm spacing and the Mn distribution are in a very good agreement with the experimental results. Additionally, the resulting non-standard dependencies of the arm spacing on the process parameters are compared with analytical calculations, which show excellent agreement between predictions and experimental measurements.

We employed phase-filed models to simulate microstructure evolution and solidification behaviour of AlSi10Mg alloy produced using direct metal laser sintering (DMLS) technique. We explored numerically, the dendritic morphology and orientations for a range of cooling rates and thermal gradients, focusing on the columnar-to-equiaxed transition (CET) of DMLS-AlSi10Mg. A new efficient numerical approach was also introduced to model the heterogenous nucleation of inoculant particles that triggers CET. The results of this work are expected to provide a reference for a future study on the effect of the building direction and scanning strategy on the microstructure and texture of DMLS-AlSi10Mg.

Many researchers have focused on thermal, structural or other multiphysics modelingModeling of laser and electron beam powder bed processes. However, in most cases, the laser heat source distribution is considered Gaussian as an ideal beam. However, power intensity distribution is a function of many parameters that need to be considered if realistic modelingModeling of laser interaction with surface is desired. This work seeks to model the process in a more comprehensive and realistic manner by taking the laser physics into consideration including the wavelength, laser quality factor and laser beam parameter product. The model also uses a level setLevel Set method to determine the shape of the bead and melt poolMelt Pool during meltingMelting and solidificationSolidification process. Other physics including the heat transferHeat transfer and fluid flow is incorporated in the simulationSimulation to model the whole process. This multiphysics process is used to model the melt poolMelt Pool geometry. Results are compared against an experiment for Inconel 718 alloy.

Unique and ultrafine microstructures are achieved through metal powder bed fusionPowder Bed Fusion additive manufacturingAdditive manufacturing (AM) processes. However, a gradient in the microstructureMicrostructure through the height of tall-enough samples can be observed due to different cooling rates and heating–cooling cycles experienced by different locations. In the current study, a vertically built sample of AlSi10MgAlSi10Mg with a rectangular cross section was manufactured through direct metal laser sintering (DMLS)Direct metal laser sintering (DMLS) process. The microstructureMicrostructure was studied at the bottom and top of the sample. From the bottom to the top of the DMLSDirect metal laser sintering (DMLS) -AlSi10Mg AlSi10Mg sample, fewer heating–cooling cycles were experienced by the material. Moreover, the cooling rate was different due to change of the thermal boundaries and cooling conditions. The microstructureMicrostructure of the DMLSDirect metal laser sintering (DMLS) -AlSi10Mg AlSi10Mg was analyzed using multi-scale characterizationCharacterization techniques including EBSDEBSD and APTAPT . The microstructureMicrostructure characteristics were correlated to the solidificationSolidification conditions experienced by the material.

Distribution of particles in metal matrix composites has a crucial effect on the efficiency of the mechanical reinforcing process. Re-meltingMelting and solidificationSolidification of the matrix due to laser energyEnergy input during selective laser meltingSelective laser melting increases the probability of the secondary phase agglomeration. Reinforcement particles reallocate locally based on the speed of the solidificationSolidification front through formation of the melt poolMelt Pool . Adequate energyEnergy input and optimized scanning speed are required not only to assure consolidation of the product, but also to control the melt poolMelt Pool geometry and solidificationSolidification rate and consequently avoid particle pushing and clustering. A finite element modelFinite element model was developed to exhibit the interaction of aluminumAluminum nitride particles with the AlSi10MgAlSi10Mg melt poolMelt Pool with respect to the solidificationSolidification front. The model shows that the critical solidificationSolidification conditions define whether engulfing or particle pushing take place; as an essential consideration when manufacturing metal matrix composites through selective laser meltingSelective laser melting .

The GH4169 alloyGH4169 alloy steelSteel is used to fabricate the gas turbine blades. It is required to withstand a gas stream temperature of 1600 °C and have a heat transferHeat transfer rate of a domestic central heating system. For the regular grain growthGrain growth under directional solidificationSolidification condition, we study on how to select a single-crystal grain in the spiral grain selector. The purpose of the numerical simulationNumerical simulation technique using the solidificationSolidification process is not only to obtain the distribution of the temperature field or the flow field, but also to examine the single grain microstructureMicrostructure growing process based on the café module contained in Procast software. The simulationSimulation results show that the data basis for the analysis of the solidificationSolidification of GH4169 alloyGH4169 alloy provides details on the grain morphology and a more accurate theoretical result for real as-cast products.

Packing densityPacking density of metal powdersMetal powders is an important aspect of additive as it directly impacts the physical and mechanical propertiesMechanical properties of printed products. In order to achieve the most efficient packing of a powder, different grades of that powder must be mixed together in such a way that we minimize the voids. Research has shown that packing the coarser grains first not only yields higher density powders but also decreases balling defects in the finished printed product. In this study, we developed a simple model that adequately predicts the volumetric fractions of different powder grades that can yield the highest powder density. The model accounts for the disparities between theoretical assumptions and experimental outcome, such as volume reduction. The model equations, based solely on void ratios and true specific gravity, will be validated experimentally and compared to other modelingModeling efforts in literature to further prove the potency of the model.

A digital twinDigital twin is an image of the reality. In case of a digital twinDigital twin for additively manufactured components by the use of selective laser meltingSelective laser melting and Inconel®718 issues as microstructureMicrostructure , anisotropyAnisotropy and load history are discussed. In order to take the main influences on the cyclic material behaviorCyclic material behavior into account, local stresses and strains of a structure elementStructure element are introduced. Furthermore, this new interpretation of the local load properties enables a two-stage combined macroscopic and microscopic material image as the basis for a digital twinDigital twin for the fatigueFatigue assessment of additively manufactured components.

The design flexibility offered by the newest additive manufacturingAdditive manufacturing technologies is attracting the attention of the automotive industry for the realization of safety-relevant components. However, the realization of complex geometries is characterized by the use of support structures which sustain surfaces with downskin angles lower than 45°. The subsequent removal of these punctual joints leaves the surface irregular and with a large amount of defects. In this work, the effect of surface imperfections on the cyclic stress–strain behaviorCyclic stress–strain behavior of additively manufactured metals is evaluated. Small-scale specimens are manufactured by selective laser meltingSelective laser melting of AlSi10MgAlSi10Mg powder. The specimens are manufactured using different build orientations, part of them are left as-built while the surface of other specimens has been polished. Incremental step tests are carried out in order to evaluate the cyclic stress–strain behaviorCyclic stress–strain behavior of this material.

Over the last decade, additive manufacturingAdditive manufacturing (AM) techniques have been expanding rapidly due to their ability to produce complex geometries with an efficient use of material. In order to design reliable AM parts, the mechanical propertiesMechanical properties resulting from the manufacturing process need to be understood. The present study investigates the fatigueFatigue of AM Ti–6Al–4VTi-6Al-4V and 316L316L . Miniaturized Ti–6Al–4VTi-6Al-4V and 316L316L specimens were manufactured using laser powder bed fusionLaser powder bed fusion (L-PBF). The geometry, process parametersProcess parameters , and loading conditions were kept constant and the specimens were tested in as-built surface condition. The S-N curves of as-built, stress-relieved and HIP’ed specimens were measured, and an analysis of the microstructureMicrostructure , relative density and surface roughnessSurface roughness was performed. The effect of fatigueFatigue influencing factors (residual stresses, surface roughnessSurface roughness , porosityPorosity and microstructureMicrostructure ) was systematically investigated. In order to understand the fatigueFatigue failure mechanismMechanism , identification of crack initiationCrack initiation point, via fracture surfaces analysis, was performed.

Metals fabricated in a powder-bed environment can achieve outstanding mechanical propertiesMechanical properties . AluminiumAluminium -silicon (AlSi) alloys can exhibit an anisotropic behaviour and exhibit inhomogeneities and predetermined sites of fracture in their as-fabricated state. The work at hand provides an overview of the fracture toughnessToughness and the fatigueFatigue performance of selective laser melted AlSi, including surface treatments and the impact of the irradiation paradigm. In addition, the results of conventional post-heat treatments on selective laser melted material as well as their limitations are discussed.

Ni–Ti alloys have achieved great importance in industry, mainly for their innovative use in practical medical applicationsApplications . A major reason for that is their fatigueFatigue lives. In this research, fatigue lifeFatigue life of different Ni–Ti alloys has been investigated for different compositions of Ni–Ti alloyNi–Ti Alloy samples and different percentages of copperCopper additions. Three major compositions were investigated under different fatigueFatigue loadings. The first group of samples had a composition of Ni47.8Ti42.2, and the remaining 10% was copperCopper . A second group of samples had a composition of Ni52.8Ti42.2 and 5% of copperCopper , and a third group pf samples had a composition of Ni47.8Ti47.2 and 5% of copperCopper . These samples were prepared by casting. Comparison between fatigueFatigue lives of the prepared samples and the Ni52.8Ti47.2 sample was made, once without heat treatmentHeat treatment of samples and once with heat treatmentHeat treatment to find the best alloy composition with the best fatigue lifeFatigue life . It was found that adding copperCopper would improve the fatigue lifeFatigue life of NiTi such that Ni has significantly higher percentages than Ti. Moreover, heat treating the NiTiCu alloy would improve its fatigue lifeFatigue life by almost 10%.

The scientific exploration and exploitation of the ocean resource is now proceeding at a greatly accelerated rate. Consequently, it is required that shipbuilding steelSteel must possess high strengthStrength and toughnessToughness . In this comparative study, the inclusion, microstructureMicrostructure and impact toughnessImpact toughness of an E36 shipbuilding steelE36 shipbuilding steel , with and without addition of yttriumYttrium , were investigated. The results show that the elongated MnS inclusions in E36 steelSteel were replaced by spindle and spherical inclusions containing yttriumYttrium upon addition of 0.023 wt% yttriumYttrium , leading to the formation of the E36Y steelSteel . The microstructureMicrostructure of test steels was characterized through the ferrite and pearlite phases. The addition of yttriumYttrium decreased the pearlite lamellar spacing and refined the pearlite laminae. Furthermore, the impact toughnessImpact toughness of test steelSteel increased significantly at different temperatures; both the longitudinal and transverse impact fracture displayed ductility characteristics; and the anisotropyAnisotropy of longitudinal and transverse impact toughnessImpact toughness decreased significantly.

The relationship between the microstructureMicrostructure , mechanical propertiesMechanical properties and martensitic phase transformationMartensitic phase transformation of N-containing Co–26Cr–5Mo–5W alloys by selective laser meltingSelective laser melting (SLMSLM ) is studied. The high-resolution transmission electron microscope and X-ray diffraction observations show that two phases (ε and γ phase) co-exist in N-free alloys. In contrast, a significant decrease of ε phase is observed in N-containing alloys. It is believed that the stabilization of γ phase in N-containing alloys results from the lattice distortion and Si-rich fine-distributed precipitates that block the motion of dislocations. Both the ultimate tensile strengthTensile strength and 0.2% proof strengthStrength can be significantly improved by nitrogen addition. Interestingly, the elongation slightly increases as well. They are ~1385 MPa, ~1140 MPa, and ~18.4% for 0.08 N-containing Co–26Cr–5Mo–5W alloys, respectively. It is clear that nitrogen addition during the SLMSLM processing could be a promising strategy to fabricate Co–Cr–Mo–W alloysCo–Cr–Mo–W alloys with an excellent combination of strengthStrength and ductility by suppressing face-centered cubic (fcc) → hexagonal close-packed (hcp) martensitic phase transformationMartensitic phase transformation .

A new Wire-Arc Additive ManufacturingAdditive manufacturing (WAAM) technique is used to produce Nickel Aluminum Bronze (NAB)Nickel Aluminum Bronze (NAB) components for marine applicationsApplications in view to mitigate the problems that typically arise in a cast microstructureMicrostructure . In cast condition, the alloy typically exhibits microstructureMicrostructure that consists of an FCC Cu-rich solid solution (or α-phase), some retained β-phase, and several intermetallic phasesIntermetallic phases collectively referred to as κ-phase. This study aims to characterize the crystal structures of the various κ-phases or precipitates, their distribution, morphology, orientation relationships with the α-matrix, and their chemical compositions in WAAM-NABNickel Aluminum Bronze (NAB) alloy using electron microscopyElectron microscopy . The precipitationPrecipitation of κ-phase differs in morphology and chemical composition to those present in a cast NABNickel Aluminum Bronze (NAB) . In addition, some uniaxial tensile coupons were machined out of the WAAM-NABNickel Aluminum Bronze (NAB) samples, where tensile mechanical propertiesMechanical properties are superior to those of cast NABNickel Aluminum Bronze (NAB) . The effects of microstructural differences in both alloys on the mechanical propertiesMechanical properties are correlated.

Martensitic hardenable (maraging) stainless steels are of interest due to their combination of high strengthStrength and ductility along with superior corrosionCorrosion and stress corrosionCorrosion cracking properties. Corrax maraging steelSteel has been recently atomized in powder form for laser-based sintering applicationsApplications . In the current study, Corrax with a nominal composition of 11–13% Cr, 8.4–10% Ni, 1.1–1.7% Mo, 1.2–2% Al and 0.05% C (in wt%) was additively manufactured through direct metal laser sintering (DMLS)Direct metal laser sintering (DMLS) process. This additive manufacturingAdditive manufacturing technique results in ultrafine microstructures with unique micron and submicron characteristics. The microstructureMicrostructure of the as-built DMLSDirect metal laser sintering (DMLS) -Corrax was investigated using SEM, EBSDEBSD , and TEMTEM . The result of the current study is the preliminary step to develop additively manufactured high strengthStrength Corrax stainless steels for various applicationsApplications .

Inconel 718 superalloySuperalloy has been widely used in the aerospace field. In this study, the effect of linear heat input and laser mode on the microtextureMicrotexture and tensile propertiesTensile Properties of laser powder-deposited (LPD) Inconel 718 was studied. Continuous-wave (CW) and quasi-continuous-wave (QCW) laser modes were conducted in the experiments. The results showed that under low linear heat input, the microtextureMicrotexture morphologies with CW LPD and QCW LPD were long directional columnar grains and chaotic grains, respectively. The grain size of QCW LPD is finer than that of CW LPD. With the increase of linear heat input, the directivity of microtextureMicrotexture morphology with CW LPD becomes unobvious, while the microtextureMicrotexture morphology of QCW LPD changes little with enlarged grain size. Due to the finer grain size, the tensile strengthTensile strength at 600 ℃ of sample with low linear heat input (60 J/mm) and QCW laser mode is 17.7% higher than that with high linear heat input (120 J/mm) and CW laser mode.

Since bioresorbable metal alloys like magnesiumMagnesium and iron are highly interesting in biomedical applicationsBiomedical applications , significant efforts have been made to decrease the degradationDegradation rate of magnesiumMagnesium alloys, as well as to increase the degradationDegradation rate of iron-based alloysIron-based alloys . Since silver is known to act as an effective cathode for iron, in addition to its antibacterial behaviour, it is gaining more interest as an alloying element for iron. Unfortunately, silver itself corrodes extremely slowly, and the effect of silver in the nanoscale on the human organism is, up to now, still controversial. Therefore, new silver alloys based on rare earth elements, as well as on typical elements for biomedical applicationsBiomedical applications (Ca, Mg, Zn) with an adapted degradationDegradation profile (rate, scale of corrosionCorrosion products), are a focal point of this work. Due to the immiscibility of iron and silver, it is not possible to cast iron–silver X-alloys, but it is feasible to manufacture these alloys using powder-based additive technologies.

To improve the solidificationSolidification process of laser beam meltingLaser Beam Melting (LBM), and thus enable the printing of hard-to-weld high-strengthStrength aluminum alloysAluminum alloys , the project is designed to modify the powder surface by adding nanoparticlesNanoparticles for a guided nucleationNucleation . In situ testing of the fast meltingMelting and solidificationSolidification process of single particles will be performed using differential fast scanning calorimetry (DFSC). DFSC results will be transferred to LBM of aluminum alloysAluminum alloys and used to adjust parameter settings. Specimens will be printed, to check crack formation and physical as well as mechanical material properties. The aluminumAluminum alloy EN AW-7075 (EN AW-AlZnMgCu1.5, Al7075) is the most common high-strengthStrength aluminumAluminum alloy used in mechanical engineering, aircraft industry and, due to new developments like press quenching, also in the automobile industry. Due to the importance of Al7075, this research focusses on inoculating its powder particles and thus, enables crack and porosityPorosity free 3D printing.

The porous TiPorous Ti /TiC compositeComposite , where TiC behaviors as alloy reinforcement, with 50% porosityPorosity , was successfully prepared by powder metallurgyPowder metallurgy technology using acicular urea as space holder. The pore size in Ti foams is mainly in the range of 500–800 µm with average size of 600 µm, which is a little smaller than that of urea particles due to the pore-shrinking effect during the sintering process. On the other hand, the porosityPorosity and compressive strengthStrength of the prepared Ti products in this work increase as the adding content of TiC reinforcementTiC reinforcement , from 50.61% and 68.93 MPa for 0% TiC, to 53.08% and 106.32 MPa for 8% TiC, respectively. Results indicated that through adding TiC reinforcementTiC reinforcement into porous TiPorous Ti , the pore structure, namely, the microstructureMicrostructure , in line with the mechanical behaviors of Ti foams could be dramatically affected, with finer pore structure and enhanced mechanical propertyMechanical property obtained in the final prepared Ti foams.

Haynes® 282® is a superalloySuperalloy that offers excellent creepCreep resistance up to 0.7 of its meltingMelting point. Promoted by aerospace industries, recommending a sound process window for additive manufacturingAdditive manufacturing of this material is critical. In this study, the processing conditions were optimized by fabricating 84 test cubes using 36 different parameter sets. Thereafter, selected samples were solution annealed followed by a two-step aging for all. The cubes were optically analyzed for their porosityPorosity and defects to select the most promising parameters. Scanning electron microscopyElectron microscopy (SEM) technique was employed to characterize those features. It was observed that selection of improper parameter combination has adverse effect on the porosityPorosity of the material and may cause systematic material cracking. Existing cracks were analyzed regarding their size and orientation pattern among selected and representative samples.

Tensile deformation behavior and the TRIPTRIP effect of 1 GPa-grade TRIP-aided multi-microstructureMicrostructure (TRIP)TRIP steels were studied by in situ neutron diffractionNeutron diffraction experiments during tensile test. The effect of retained austeniteRetained austenite (γR) shape on TRIPTRIP effect in the 1 GPa-grade TRIP steels was focused on. In the static tensile tests, the 1 GPa-grade TRIP steelSteel with the γR shape of needle-like showed better uniform elongationUniform elongation , whereas the tensile strengthTensile strength was almost the same as the TRIPTRIP steelSteel with the γR shape of blocky. The reasons for the better uniform elongationUniform elongation of the needle-like TRIPTRIP steelSteel were discussed from the viewpoints of phase strain and deformation-induced martensitic transformation behavior obtained by the neutron diffractionNeutron diffraction experiments. As a result, the difference of phase strains and the transformation rate are found to play an important role in the better uniform elongationUniform elongation .

Stelco has developed a suite of Advanced High-Strength SteelsAdvanced high-strength steels (AHSS) grades with tensile strengthTensile strength greater than 1000 MPa to meet standard automotive specifications and for unique customer requirements. These grades were optimized by correlating chemical composition and processing parameters with microstructures and mechanical propertiesMechanical properties . Dual-Phase 980 (Stelco trademarked STELMAXTM980DP), MultiphaseMultiphase 1180 (STELMAXTM1180MP), Martensitic 1300 (STELMAXTM1300M) and 1500 (STELMAXTM1500M) products met strengthStrength and formability requirements with excellent flatness and consistent mechanical propertiesMechanical properties across the entire strip length and width by using hydrogen quench continuous annealingAnnealing technology.

The lath martensiteLath martensite in steelSteel is the basic structure which brings the high strengthStrength on many types of advanced high-strength steelsAdvanced high-strength steels (AHSSs). The properties of AHSSs depend on the strengthening mechanismMechanism of martensite. However, the mechanismMechanism is not clear because of the complex substructure of lath martensiteLath martensite . In this study, we evaluated the effects of solute carbonSolute carbon content and prior austenite grain size on the yield strengthYield strength of fully lath martensiteLath martensite structure in low and ultra-low carbon Fe-Ni alloys. Although the grain refinementGrain refinement increased the strengthStrength in low-carbon alloys, it did not affect in the interstitial-free alloy. The Hall–Petch coefficient increased with the carbon content increasing, and saturated gradually. This behavior was similar to that in the ferritic steelSteel , and more carbon content was required for the saturation in the lath martensiteLath martensite .

Work hardening, grain boundary, substructure and texture strengthening are the most significant hardening mechanisms that influence the strengthStrength of microalloyed steels during deformation below non-recrystallization temperature. What is more, their mechanical response is a result of primary processing, where precipitationPrecipitation and solid solution strengthening play an important role. In practice, many room temperature metal forming operations involve cyclic strain path changes that introduce complex loading conditions. Thus, in the present work, the effects of cyclic strain reversal on microstructureMicrostructure and texture development in microalloyed steelMicroalloyed steel were studied using room temperature torsion tests. High-resolution EBSDEBSD was used to analyse the microstructureMicrostructure and texture evolution at different stages of cyclic deformation. A similar analysis was also performed using low-carbon steelSteel as a reference material. The analysis was focused on substructure formation and rotation mechanismMechanism as a result of strain reversal in both steels. Finally, conclusions regarding the effects of strain reversal on abovementioned strengthening mechanisms were drawn.

Lath bainitic steels with uniformly distributed carbon-rich austenite have been gradually applied in automotive industry and other fields due to high strengthStrength and toughnessToughness performance. Newly designed Nb–Ti microalloyed carbide-free bainitic steels with three different Nb contents ranging from 0 to 0.046 wt% by air-cooling after being forged instead of austempering have been investigated. The results show that all microstructures consist of bainitic ferrite and austenite with morphologies of retained austeniteRetained austenite film and M/A islands. Moreover, the increased Nb content leads to the increases in the amount of lath bainite and retained austeniteRetained austenite from 22.4% to 89.4% and from 7.4% to 11.4%, respectively. Furthermore, the yield strengthYield strength is enhanced from 791 to 850 MPa attributed to phase transformationPhase transformation strengthening of lath bainite and precipitation strengtheningPrecipitation strengthening of (Nb, Ti)C. The impact energyEnergy is improved from 33 to 86 J owing to the increased amount of retained austeniteRetained austenite film and high misorientation angle grain boundaries.

High-strengthStrength steels are widely used with marine resource exploitation. However, the marine environment is harsh, especially in special marine environment with high salt spray, high humidity, or alternating wet and dry environment. Thus, corrosion behaviorCorrosion behavior of high-strengthStrength steelSteel in harsh marine environment has become a highly significant topic. The effect of Y-based rare earthY-based rare earth (RE) on the inclusion modificationInclusion modification and corrosion behaviorCorrosion behavior of EH36 shipbuilding steels has been investigated. The results demonstrate that the elongated MnS inclusions in EH36 steelEH36 steel , noticeable in the absence of RE, were replaced by spherical RE complex inclusions upon addition of 0.029 wt% RE, leading to the formation of the EH36RE steelSteel . Furthermore, the addition of Y-based RE effectively improves the corrosion resistanceCorrosion Resistance . Y-based RE addition inhibits the precipitationPrecipitation of MnS, restrains the initiation of corrosionCorrosion . The electrochemical test exhibits a decrease passive current as well as a higher resistance of the EH36RE steelSteel .

In recent years, more and more ultrahigh strengthStrength steels are used in automotive industry, including dual-phase steels and complex phase steels, which are formed using cold stamp forming and roll-forming process. In this paper, a cold rolledCold rolled ultrahigh strengthStrength steelSteel was studied, and different intercritical annealingIntercritical annealing parameters were adopted to get different microstructures of the steels. Scanning electronic microscopy (SEM) and transition electronic microscopy (TEM)TEM were used to analyze the microstructure evolutionMicrostructure evolution of the multiphaseMultiphase ultrahigh strengthStrength steels. Tensile tests and hole expansion tests were also adopted to evaluate the mechanical propertiesMechanical properties and hole expansion properties of the multiphaseMultiphase ultrahigh strengthStrength steels. The results show that with increasing intercritical annealingIntercritical annealing temperatures, the yield strengthYield strength and ultimate tensile strengthTensile strength of the steels increase with elongation decrease simultaneously, furthermore the yield ratio is also improved. The microstructureMicrostructure of the steels contain a mixture of bainite, martensite and ferrite, and with increasing annealingAnnealing temperatures, the content of martensite decrease. Meanwhile, the content of tempered martensite increase gradually. With increasing annealingAnnealing temperatures, the hole expansion ratioHole expansion ratio increases first and then slightly decreases.

The effect of Cu and Ni addition on mechanical behaviorMechanical behavior of HSLA X100 steels containing relatively low amount of Carbon was studied. Very high strengthStrength , the appropriate level of toughnessToughness and good weldability attained through low carbon addition have made these steels a very attractive choice for the shipbuilding applicationsApplications . Thermomechanical controlled processing was applied on the cast samples with various amounts of Cu and Ni, and the effect of process variables on mechanical propertiesMechanical properties were investigated. Austenitization and quenching together with temperingTempering were also applied on the thermomechanically produced samples. Mechanical propertiesMechanical properties were evaluated by tensile, hardnessHardness and Charpy impact tests. Microstructural evaluation was done by Optical and Scanning Electron Microscopies. Results showed that by adding Ni and Cu up to 7.6% and 4.1%, respectively, it is possible to obtain yield strengthYield strength above 160 ksi. This was achieved while toughnessToughness was still in an adequate level.

La(Fe,Co,Si) $$_{13}$$ compounds exhibit a giant magnetocaloric effect, and they are considered as a good magnetocaloric working substance for an environmentally friendly cooling technique. The insertion of light elements (H, C) is used to improve the Curie temperature near room temperature for magnetic refrigeration applications. We have developed a method combining high energy ball milling with a subsequent short annealing treatment to obtain a single phase compounds. Moreover, one single step of reactive spark plasma sintering was used. The insertion of H atoms was carried out using a Sievert apparatus and the carbon atom was inserted by solid/solid reaction. Structural and magnetic results were carried out by neutron diffraction and Mössbauer spectroscopy. The misunderstanding on interstitial site is clarified. The magnetovolumic effect on the Curie temperature is explained by the combination of the structural and magnetic properties.

Fe-3Si-3Al and Fe-4Si-4Cr (wt%) experimental alloys were processed to assess the electrical resistivityResistivity and workability Workability effects of substituting Al and Cr for Si in high-Si electrical steelSteel alloys. The experimental alloys were made by arc meltingMelting , and processed by hot rollingRolling and cold rollingCold rolling to produce strips. Samples were characterized by means of metallography, hardnessHardness , workability Workability and resistivityResistivity . Results showed that the two alloys could be rolled down to 200 µm thicknessThickness (90% hot-rolled reduction and 80% cold rolledCold rolled reduction) without crack formation in the strips. HardnessHardness in the annealed condition and electrical resistivityResistivity were 228 HV/74 µΩ cm and 243 HV/85 µΩ cm, respectively, for the Fe-3Si-3Al and for Fe-4Si-4Cr alloys. The resistivityResistivity measured for Fe-4Si-4Cr was higher than the resistivityResistivity reported for the benchmark high-Si alloy, Fe-6.5Si. Both experimental alloys showed improvement on the workability Workability compared to Fe-6.5Si since there was no edge cracking on the cold-rolled strips up to 80% reduction, and the hardnessHardness was approximately 35% lower.

Pr–Co-based intermetallic compounds are candidates for permanent magnets and magnetocaloric effect. Samples have been synthesized by ball milling method with a subsequent fast annealing treatment. While the long-range order obtained by standard X-ray powder diffraction is commonly used to describe the structure and try to understand the exceptional properties of these materials, it is necessary to get a better knowledge of the local environment around each component using local probes. In the iron-substituted materials PrCo $$_{3-x}$$ Fe $$_x$$ , the purpose is to find the substitution of cobalt by iron site. Since the relative concentration in iron is not favorable to Mössbauer studies. Magnetic measurements and magnetocaloric effect were performed using magnetometer measurements. The optimum extrinsic magnetic properties have been obtained for Pr $$_5$$ Co $$_{19}$$ with a coercivity of 1.5 T at room temperature. Furthermore, these uniaxial anisotropic compounds exhibit a large magnetic entropy change at Curie temperature. $$\Delta S_\text {max}$$ is equal to 5.2 J/(kg K) under low magnetic field of 0–1 T. These results indicate that these nanomaterials are suitable for permanent magnet applications and for magnetic refrigeration.

Nowadays, the demand for hybrid electric vehiclesElectric Vehicles (HEVs) is increasing to control harmful gas emissions. In HEVs, batteriesBatteries play a vital role as a power source. Generally, aluminumAluminum and copperCopper of micro thicknessThickness are being used as electrodes, and each of the cells are interconnected to bus bars of the same material. The challenge is to achieve the appropriate joining of micro-thick sized sheets and to have maintain good electrical conductivityElectrical conductivity of the joints. The present study is focused on the joining between pure copperCopper of 0.3 mm and pure aluminumAluminum of 0.2 mm, in a lap configuration by using friction stir welding process. A 4-probe high-temperature resistivityResistivity test was carried out to measure the electrical conductivityElectrical conductivity of the welded samples. The electrical conductivityElectrical conductivity of the welded joint was depending on the proper material mixing, and IMCs formation at the interface.

In microelectronic industry, high-strength and high-conductivityHigh strength and high conductivity wire was a hot topic recently. In this work, the Cu–0.3 wt%Ag alloy was prepared and the severe cold plastic deformation treatment with a maximum true strain η of 11.48 was applied to obtain the Cu–0.3 wt%AgCu–0.3 wt%Ag ultra-fine wiresUltra-fine wires with the diameter of 0.087 mm. Then the ultra-fine wiresUltra-fine wires were given different heat treatments. Mechanical propertiesMechanical properties and electrical properties of the ultra-fine wiresUltra-fine wires with different annealingAnnealing heat treatments were investigated, and the microstructure of them was observed by scanning electron microscope (SEM) and optical microscope (OM). Results showed that the tensile strengthTensile strength and conductivity of Cu–0.3 wt%Ag ultra-fine wire in the hard state could reach 659.41 MPa and 95.24%IACS, respectively. Compared with pure CopperCopper , Cu–0.1 and Cu–1.0 wt%Ag fine wires, the Cu–0.3 wt%AgCu–0.3wt%Ag fine wire exhibits the superior comprehensive property and is a promising high-strength and high-conductivityHigh strength and high conductivity material.

High temperatureHigh temperature solderSolder alloys are characterized by meltingMelting temperatures between 230 and 400 °C. They are commonly used as component joining material in electronics and automotive industries. Characteristics such as excellent wettability, suitable mechanical propertiesMechanical properties and oxidation resistance made lead-based Pb–Sn alloys widely used for such applicationsApplications . However, the toxicity of lead, associated with environmental risks and human health caused by the undue disposal of these materials restricted the employment of these alloys. Under such circumstances, new high temperatureHigh temperature alloys have been recently developed. Zn–Sn alloys are considered promising for the substitution. However, improvements in the mechanical propertiesMechanical properties , wettability and some other application properties are required. These are expected to be achieved with the addition of third alloying elements such as Ag or Cu. The present work aims to evaluate the addition of 2.0 wt% of Cu in the resultant microstructureMicrostructure constituting the Zn–20 wt%Sn alloy. Also, effects of the Cu alloying over solidificationSolidification thermal parameters must be pondered. For this purpose, data from a directionally solidified (DS) Zn–20 wt%Sn–2 wt%Cu alloy will be compared with results found in literature for the DS Zn–20 wt%Sn alloy. Microstructural analyzes were performed using SEM, optical microscopies and X-ray diffraction. The microstructures consist of Zn-rich phase in the form of plate-like cells; intercellular regions containing eutectic mixture (Zn-α + Sn-β) and the CuZn5-ε intermetallicIntermetallic phase. Experimental analysis resulted in mapping the growth variations of cell spacing against cooling rate and growth velocity. The cell spacing was shown to be vital to maximize the tensile propertiesTensile Properties of Zn–Sn–Cu soldersSolders .

Due to the toxicity of Pb in the soldering alloys, new alloys (lead freeLead free ) are suggested by scholars especially for high-temperatureHigh temperature applicationsApplications . One of the alloys recommended so far is Bi–AgBi-Ag . This alloy has certain similar features to Pb–Sn alloys. Thus, the study focused on several candidate alloys (Bi–1.5–2.5–3.5 wt%Ag) as alternative soldersSolders . In this paper, the mechanical propertiesMechanical properties were studied using shear testShear test . It can be found from the shear testShear test results that increasing the amount of Ag content in the solderSolder matrix positively impact the maximum shear stress and shear strain. The highest maximum shear stress and strain were observed at Bi–3.5 wt%Ag with the value of 13.355 MPa and 44.136 MPa, respectively. Furthermore, the lowest maximum shear stress and strain were observed at Bi–1.5 wt%Ag with the value of 11.032 MPa and 24.955 MPa, respectively. Hence, the fracture behavior shifted from brittle to ductile.

This paper develops a parametrically homogenized continuum damage mechanics (PHCDM) model for unidirectional fiber-reinforced composites undergoing progressive damage. The PHCDM models are designed to overcome limitations of prohibitive computational overhead associated with many homogenization methods. They are thermodynamically consistent, reduced-order continuum models with explicit representation of microstructural morphology. The PHCDM model is derived from detailed micromechanics of representative volume element (RVE) using energy equivalence principles. Micromechanical failure is due to fiber–matrix interface debonding and matrix cracking. The macroscopic PHCDM models represent damage anisotropy through a second-order damage tensor that contributes to the evolution of a damage surface in the space of damage work conjugate. The damage surface characterizes the initiation and evolution of damage. The constitutive relation between damage and its work conjugate is represented by an anisotropic fourth-order damage surface tensor $$P_{ijkl}$$ , whose components are expressed as functions of current damage state and composite morphology. These are calibrated and validated from homogenized micromechanical (HMM) responses. The PHCDM model is incorporated in a commercial finite element code, and analysis of macroscopic composite components is executed for understanding concurrent damage at multiple material length scales.

Casting process is widely used in preparing spur gearSpur Gear blanks or in complete production of gearsGears because of its less defect at the end of the process. The importance of the gating system in casting process lies in its ability to channel molten metal into the mould cavity within the allowable period at a controlled parameter. The study therefore investigated the effect of increasing the gating system on the solidificationSolidification of molten metal during gear cast to determine the time of solidificationSolidification and casting productivity. Both the top and bottom gating system were modelled in solidwork, while the simulationSimulation was done using Pro-Cast. The result revealed that for the case of two runner gating system, both the top and bottom gating system took 9.195 and 9.320 s respectively, to fill the mould cavity. However, the three-runner gating system took a shorter filling time with top gating system having 8.824 s filling time and the bottom gating system took about 9.655 s to fill the mould cavity. The outcome showed that the top gating system tends to discharge molten metal faster than the bottom gating system as seen from the filling time of both the two and the three-gating system.

Two-dimensional nanomaterials, such as grapheneGraphene , boron nitride nanosheetsNanosheets (BNNS), molybedenum disulphide nanosheetsNanosheets , have been extensively researched for various applicationsApplications . CorrosionCorrosion protection of metals with the help of coatings is also one of the areas where the potential of these nanomaterials has been explored. Recent reports showed grapheneGraphene -based coatingsCoatings can improve corrosion resistanceCorrosion Resistance of metals in the sea environment. This study aims to evaluate corrosionCorrosion protection ability of BNNS deposited on CopperCopper (Cu) metal. BNNSs were developed from boron nitride particles by ultrasonicating them in isopropanol for 8 h followed by separation using centrifuge. The supernatant, colloidal solution of BNNS/isopropanol, obtained by centrifugation was mixed with few drops of reduced grapheneGraphene oxide/water suspension to achieve BNNS deposition by electrophoretic depositionElectrophoretic deposition , which employed Cu metal as cathode and platinum as anode. The as-developed BNNS coatingsCoatings on Cu were characterized for their morphology, functionality, composition and structure using scanning electron microscope, Fourier transform infrared and Raman spectroscopy, energyEnergy dispersive x-ray analysis and x-ray diffraction, respectively. The corrosion behaviorCorrosion behavior of coatingsCoatings was studied by Tafel analysisTafel analysis , electrochemical impedance spectroscopy (EIS) and cyclic voltammetery in 3.5% NaClNaCl solution. Tafel analysisTafel analysis showed that BNNS coatingsCoatings improved corrosion resistanceCorrosion Resistance of Cu metal by five times. EIS analysis showed high impedance and capacitive behavior of BNNS coatingsCoatings .

In this study, sol-gelSol-gel process followed by electrodepositionElectrodeposition process was used to prepare a ZrO2 ZrO2 coatingCoating on the Fe–Al alloyFe–Al alloy layer. The sol-gelSol-gel process is prone to produce pores. We studied the effect of pulling speed on the ZrO2 ZrO2 coatingCoating . The electrodepositionElectrodeposition process was further used to densify the coatingCoating . The deposition time had a significant effect on the porosityPorosity . The surface and cross-sectional morphology of the coatingCoating was observed by scanning electron microscope, and the phase structure was detected by X-ray diffraction. The results revealed that the ZrO2 ZrO2 coatingCoating when being pulled at 120 mm/min had the minimum porosityPorosity of 6.48%. Almost no pores were found on the surface after three times of 6-min deposition. The thicknessThickness of the ZrO2 ZrO2 coatingCoating after deposition for 6 min was about 13 μm. The internal Fe–Al alloyFe–Al alloy bond coat contained FeAl3, Fe2Al5, FeAl and Fe3Al phases, and the external ZrO2 ZrO2 coatingCoating contained t-ZrO2 ZrO2 and m-ZrO2 ZrO2 phases.

The slurrySlurry erosion wearErosion Wear behaviour of coal bottom ashCoal Bottom Ash handling pipeline was investigated with an effect of operating parameters under water-based slurrySlurry , through a slurry potSlurry Pot test rig. Mild steelMild Steel (MS) has been selected for test sample material as representative of coal ash slurrySlurry handling pipeline material. The solid–liquid mixture is prepared using coal bottom ashCoal Bottom Ash by mixing with tap water. The sieve analysis was performed to designate the particles size. The average mass loss of the two specimens has been used to evaluate the erosionErosion rate in g/g of solids. Experiments were conducted in four different sets with at 4 and 5 m/s velocity, 550 and 1500 µm particle size and 10 and 30% by weight concentration for impact angle range 7.5°–90°. A mass loss of the wearWear specimen is measured on an electronic balance with precision having least count (L.C.) of 0.1 mg. The variation of erosionErosion rate with impact angle for MS has shown the increase in erosion wearErosion Wear rate with increase in impact angle till a particular angle which decreased with further increase in the orientation angle till 90°. The maximum erosionErosion angle is found at 22.5° impact angle. The scanning electron microscope (SEM) micrographs of the worn specimens showed that the erosionErosion at maximum wearWear angle is contributed by mainly platelet formation and micro-cutting and this contribution decreases with increase in the impact angle showing only the indentation craters at 90° orientation angle. Based on these observations, it has been concluded that the particle impact angle coincides with the fixture orientation angle.

The subject covered in this paper concerns the development of an innovative PVD coated multipoint cutting tool with cemented carbideCemented carbide brazed inserts for high-speed cutting of ferrous alloys. The aim of the research was to optimize the properties of the constituent materials in order to maximize their durability and provide a constant level of surface finishing of the machined parts. The results concerning the selection of the best cemented carbideCemented carbide grade for high-speed cutting application are presented in this work; both mixed and plain grades were considered. The optimal grade of cemented carbideCemented carbide was chosen by comparing microstructural and mechanical propertiesMechanical properties such as hardnessHardness and toughnessToughness with wearWear resistance in sliding condition against AISI 4140 pins on a pin on discPin on disc tribometer. After a proper design of the optimal tool geometry, tools were tested on a CNC milling machine and tool wearWear was characterized by optical and electronic microscopy.

Due to controlled and enhanced tribological conditions in forming technology, oils are generally used. Liquid lubricants, especially mineral oils, are environmentally harmful or even toxic. Within the priority program 1676, researchers are studying technologies to prevent the use of lubricants in forming operations. One approach to avoid lubricants in sheet metal forming is the generation of thin selective oxide layersOxide layers (thicknessThickness of about 300–500 nm) on forming tools. In previous investigations, it was found that these layers (e.g. α-Fe2O3-layers) have the ability to reduce friction between the tool and sheet metal (DP600+Z) as well as zincZinc pick-up on the tool surface. Furthermore, the wearWear behavior of those layers was investigated. It could be shown that the oxide layer resists several thousand loads of stroke. Within this study, an overview of the previous work and the future activities of the task will be shown.

Laser hardeningLaser hardening of metal alloy provides the economical avenue to achieve high-performing surfaces. Complexities in geometrics and hard-to-reach surfaces can be easily handled with this process. Heterogeneous materials such as cast iron pose a challenge to achieve targeted surface properties using laser hardeningLaser hardening . It is still one of the most important materials being used in the automotive industry due to its castability, machinability, and damping. Cast iron also has better frictional performance and wearWear resistance. Its wearWear performance can further be enhanced using laser hardeningLaser hardening . In the current investigation, 400 W optic fiber laser system was employed to study the effect of process parametersProcess parameters on the selective surface area by laser hardeningLaser hardening . The laser beam power and laser scanning speed with constant laser beam diameter were used for the surface scan. Surface properties such as micro-structureMicro-structure and hardnessHardness were studied. It was observed that micro-hardnessHardness was double compared to the untreated surface.

Micro-EDMMicro-EDM process is being increasingly used for machining of micro-features on difficult-to-machine materials. But, the thermal damagesThermal damages such as micro-craters, ridge-rich surfaces, micro-pores, and recast layer, etc., are the biggest technical barrier to a wider usage of µ-EDM. In order to mitigate the obstacle of thermal damagesThermal damages , µ-ECM as a sequential finishing method was employed. The input process parametersProcess parameters , which were controlled during µ-ECM operation, are voltage and machining duration. The machined surface characteristics were analyzed using field-emission scanning electron microscopyElectron microscopy (FE-SEM) and atomic force microscopy (AFM). 3D characterizationCharacterization of the machined surfaces was done to assess the quantitative influence of the µ-ECM process on surface roughnessSurface roughness . The experimental results revealed that the µ-ECM process effectively dissolved the thermal damagesThermal damages generated during µ-EDM process. Furthermore, while overlapped micro-craters with ridge-rich surface were found in µ-EDM, 72% reduction in average surface roughnessSurface roughness of µ-EDMed surface was achieved with the sequential µ-ECM process. The improved surface integritySurface integrity of µ-EDMed Ti–6Al–4V alloyTi-6Al-4V alloy was accomplished by using µ-ECM process in sequence.

In this study, the suitability of PTFE-based coatingCoating deposited on AA3003 AluminumAluminum alloy by a non-conventional method for corrosionCorrosion and wearWear protection was investigated. The coatings were deposited from a mixture of PTFE and alumina powders at room temperature and atmospheric pressurePressure . The coatings were characterised with SEM/EDX, XRD and contact angle goniometer. The corrosionCorrosion performance of the coatings in 3.5 wt% NaClNaCl was evaluated using electrochemical impedance spectroscopy (EIS) and wearWear performance was investigated using a pin-on-disk wearWear tester. The results indicated that the coatings exhibited about threefold reductions in the wearWear rate of AA3003 alloy and a twofold increase in its polarisation resistance. This improvement was discussed in relation to the characterisation results.

In the paper, the process of Ti6–Al4–V aging phase transitionPhase transition and diffusion bondingDiffusion bonding was studied by molecular dynamicsMolecular dynamics method. The EAM potential combined with more potential was employed to deal with the interaction between the atoms of Ti–Al–V ternary alloy. The radial distribution functionRadial distribution function of Ti6–Al4–V and the relative content of different crystal structures were analyzed. The results show that the structural changes of Ti6–Al4–V in the aging phase transitionPhase transition are mainly manifested in the new phase of metastable phase. In the process of diffusion, the titaniumTitanium atoms near the interface are mainly diffused, and vanadium atomic diffusion is secondary, while aluminumAluminum atom is relatively few. Under the same conditions, the diffusion connection width and thermal insulation temperature are in a good linear relationship. In addition, the diffusion coefficientDiffusion coefficient of titaniumTitanium is exponentially related to the temperature of heat preservation. The simulationSimulation results are good agreement with the experiment.

Recent developments regarding the thermoelectric properties of pyrolytic graphiteGraphite (PG) and common metals have led to the measurement of the Seebeck coefficient between PG and several metals. In this present work, a new thermocoupleThermocouple is developed for use under high-temperatureHigh-temperature conditions such as metal casting. The excellent thermoelectric properties of PG and the high meltingMelting point of steelSteel are exploited for use as our thermoelements. The research effort was concentrated on determining the Seebeck coefficient/thermopower of the designed thermocoupleThermocouple through measuring its thermoelectric response to temperature changes as indicated by the Seebeck effectSeebeck effect . The heating experiment was done to a temperature of 500 °C and a near-linear response was obtained for the plot of the thermocoupleThermocouple output voltages against the temperature changes.

In situ mechanical tester was coupled with micro-CT to investigate the effect of alveolar bone socket geometry and implant anchorage on bone–implant contact interface and the resulting strain distributions in bone. Compressive axial load was applied to occlusal surface of teeth to simulate chewing force. Then, the teeth were extracted and dental implants were placed immediately. The same compressive load was applied to bone–implant complexes. Using image processing and digital volume correlationDigital volume correlation , the displacement and strain field in the mandible bone were calculated and compared for the bone–tooth structures and bone–implant structures. Under implant loading, high strain concentrationStrain concentration was observed in some regions in the mandible bone. In contrast, the strain distribution in bone under tooth loading was relatively uniform. The variations in the strain distribution can be attributed to the differences in the anatomies/geometries, mechanical propertiesMechanical properties and contact area with bone for implants and teeth. The clinical implications of the results are discussed for the designs of bioinspired dental implants.

In recent decades, traumatic brain injury has been at the forefront of public health and military injury research. Improved understanding of skull deformation and fracture are required to advance the development of numerical simulations and surrogate materials aimed at providing critical feedback for future protective equipment design. Numerical simulations of skull fracture require material properties and identification of fracture mechanisms for compressive, tensile, and shear loading; skull–bone failure mechanisms are complex and stress-state dependent. A knowledge gap exists on the mechanical response of human cranial boneCranial bone subjected to pure shear loading. A shear-punch experimental method was designed to understand the shear response of human skull as a function of through-thicknessThickness for cadaveric calvaria specimens. The compliance of the shear-punch system was first tested on a polyurethane foam trabecular bone simulant and a stereolithographic additively manufactured cortical bone surrogate, and their shear strengthShear strength values were compared to known values of human bone. The sandwich-like structure of human cranial boneCranial bone consists of dense outer and inner tables separated by a highly porous central diploë layer. Force data obtained from the shear-punch experiments was analyzed as a function of normalized penetration depth to assess the shear strengthShear strength compared to the microstructureMicrostructure . Preliminary results show 1% offset yield and ultimate shear strengths of human calvaria to be 17.7 ± 4.9 MPa and 25.5 ± 5.1 MPa, respectively.

The ternary Zn–Li–Cu alloy system is investigated as a potential biodegradableBiodegradable metal for orthopaedic and cardiovascular applicationsApplications . The phase composition, microstructureMicrostructure , hardnessHardness , and in vitro corrosionCorrosion rate of hot-rolled Zn, Zn–0.3Li, Zn–0.3Li–3.5Cu, and Zn–0.3Li–5Cu are examined. The addition of Li and Cu produce LiZn4 and CuZn5 binary phases within the Zn matrix, while there is no interaction between Li and Cu. Hot rollingRolling induces grain refinementGrain refinement and a rollingRolling texture with the addition of Li and Cu. The hardnessHardness substantially increases from 39.16 ± 1.49 Hv (pure Zn) to 133.85 ± 4.38 Hv (Zn–0.3Li–5Cu). Immersion-based corrosionCorrosion rate in Hanks’ solution increases with small additions of Li and Cu content due to microgalvanic behavior. Large addition of Cu promotes a lower corrosionCorrosion rate due to the noble contribution of CuZn5 phase. The outcome of this study promotes further analysis of the Zn–Li–Cu ternary system for biodegradableBiodegradable metal applicationsApplications .

For several decades, plasma processing has been employed in the areas of food processing, manufacturing, and agriculture. Plasma processing has also been recognized as greatly beneficial in the field of tissue engineering for the modification of biomaterialsBiomaterials . Polyethylene terephthalate (PET) has been employed as a vascular graft material but fails in small diameter applicationsApplications . In this work, a multifaceted approach combining electrospinningElectrospinning to produce nano- and microscale fibers from PET blended with polybutylene terephthalate (PBT) added for flexibility and plasma modificationPlasma modification for enhancing the surface chemistry is demonstrated to be an efficient approach to increase the biocompatibility as evidenced by enhanced fibroblast growth. The analysis of the surface chemistry shows an increase in oxygenated surface functionality, while the bulk analysis shows no significant changes. Thus, an efficient methodology for producing PET/PBT-based grafts that are easily modified with low-temperature plasma and show enhanced biocompatibility for vascular tissue engineering applicationsApplications is reported.

Following the introduction of additive manufacturingAdditive manufacturing technology, there have been several reports describing its efficacy for fabricating medical and dental devices. Although minimizing biofilms is important clinically, few studies have compared biofilmBiofilm accumulation on additive manufactured devices with that on alloys fabricated by other methods. Streptococcus mutans ATCC 25175 biofilmBiofilm accumulation on additive manufactured Ti–6Al–4VTi–6Al–4V ELI was compared with that on conventional dental alloysDental alloys fabricated by lost-wax casting (Commercially pure titaniumTitanium , Ti–6Al–4VTi–6Al–4V ELI alloy, Au–Cu–Ag alloy, Pd–Ag–Cu–Au alloy, Ag–Sn–Zn alloy, and Co–Cr alloy). Teflon® disks served as controls. BiofilmBiofilm accumulation on each alloy (n = 3) was conducted at 37 °C under anaerobic conditions. After 4 h, the number of metabolically active S. mutans adhering to each alloy was determined using a bioluminescence assayBioluminescence assay . Although the surfaces of the additive manufactured Ti–6Al–4VTi–6Al–4V ELI alloy were rougher than those of cast alloys, this roughness, unexpectedly, did not increase the biofilmBiofilm accumulation. Apparently, alloy composition minimizes biofilmBiofilm accumulation even when the surface is rough.

For this study, 21 smartphones touchscreen manufactured since 2010 were selected where disassembly and the printed circuit boards (PCIs) were removed. The PCIs were comminuted and characterized by magnetic separation in which the samples were fractionated in magnetic (M), non-magnetic (NM) and without magnetic separation (MIX). The chemical analyses by ICP-OESICP-OES of the digested fractions showed the presence of 1950, 857 and 1435 g/L copperCopper for the fractions NM, M and MIX, respectively. The bioleachingBioleaching tests were conducted with the A. ferrooxidans bacteria and the fraction NM and MIX. ICP-OESICP-OES analyzes the metals present in the liquor before and after the bioleachingBioleaching process and the controls (without the bacteria) showed that the presence of the bacteria increased the copperCopper extraction in 8 and 5%, which means from 6854 to 7387 mg/L and from 6309 to 6606 mg/L for the NM and the MIX fraction, respectively.

As a novel structural and functional material, the porous materials have a lot of advantages over dense ones owing to their special pore structure. Porous titaniumTitanium (Ti) with main pore size of 300–400 µm and porosityPorosity in the range of 34.0–37.5% has been manufactured by powder metallurgyPowder metallurgy (PM) technique using spherical urea particle as space holder and FeV80 powder as alloy component. The high-energyEnergy ball-milling technologyBall-milling technology was adopted to pretreat the raw powders. The compressive strengthStrength and Young’s modulus is observed in the range of 184.7–289.9 MPa and 3.17–6.62 GPa, respectively, fabricated with powders milled. Meanwhile, the datum of their counterpart materials that fabricated with powders unmilled is within the scope of 143.6–201.8 MPa and 0.86–1.15 Gpa separately. There is therefore of great significance to improve the mechanical propertyMechanical property of porous titaniumTitanium by adding a certain amount of ferrovanadiumFerrovanadium alloy or utilizing the ball-milling technologyBall-milling technology .

Titanium foamTitanium foam is considered as a potential bone substitute because of its good biocompatibility. Porous titaniumTitanium was prepared by powder metallurgyPowder metallurgy with titaniumTitanium powder used as raw material and urea as pore-making agent. The pore characteristicsPore characteristics and mechanical propertiesMechanical properties of porous titaniumTitanium with different pressuresPressure on porous titaniumTitanium were studied when the volume fraction of urea was 60%, the sintering temperature was 1100 °C, and the holding time was 1.5 h. Analysis is done by means of SEM. The results show that the porosityPorosity decreases with the increase of pressing pressurePressure , and the porosityPorosity is the lowest when the pressing pressurePressure is 150 MPa. Subsequently, due to internal defects, the porosityPorosity increased slightly. At the same time, the pore structure and mechanical propertiesMechanical properties are best when pressing pressurePressure is 150 MPa, which matches the mechanical propertiesMechanical properties required by human skeleton.

The focus of the present research is to evaluate the effect of milling times (2–48 h) on and tribological behavior of HIPed Ti–Ni. The structural evolution, mechanical properties and tribological behavior of the milled Ti–Ni alloys were evaluated in simulated body fluid (Ringer’s solution at 37 °C), using XRD, SEM and ball-on-disk tribometer. The wearWear tests were carried out in accordance with the ASTMG 99, ASTM G 133–95 and ISO 7148-1:2012 standards under different applied loads. Experimental results indicated that structural evolution and morphological changes of the milled alloys were sensitive to their milling times. The morphological characterizationCharacterization showed that the crystallite size and the particle size decrease with increasing milling timeMilling time reaching the lowest values at high milling times. The coefficient of friction and wearWear rate was lower at high milling timeMilling time . This improvement is attributed to the closed porosityPorosity and grain refinementGrain refinement .

A moving boundaryMoving boundary problem is formulated for heat and mass transfer in the solidificationSolidification of glassy alloysGlassy alloys . A similarity transformation is applied. The nonlinear system is linearized and a perturbation analysis is applied to evaluate the solution. Effects of the Fourier and Stefan numbers are obtained. This permits a closer examination of the effects of the surface conditions on the boundary layerBoundary layer and transition zone. A correlation is discovered for the boundary layerBoundary layer thicknessThickness and the glass transition temperature for many alloys in various groups of the Periodic Table, found through previously published data. In particular, the role of convective effects on the solution is used with the Biot number in the decoupling of the heat and mass components. A correlation of over 90% is found indicating a strong relationship between the Tg and the heat transferHeat transfer thermodynamic inputs. This indicated the possibility of designing BMGBMG alloys by adjusting certain parameters a priori.

For most amorphous metalAmorphous metal alloys, the requirement for rapid quenchingRapid quenching restricts the final form to be small in at least one dimension—either a powder or a ribbon. ShockwaveShockwave consolidation can yield fully dense bulk metallic glassBulk metallic glass objects from these amorphous precursors. An applied axis-symmetric pressurePressure pulse occurs so quickly that particles bond without an attendant crystalline grain growthGrain growth . For powder consolidationPowder consolidation , amorphous Fe49.7Cr17.1Mn1.9Mo7.4W1.6B15.2C3.8Si2.4 powder is first loaded into a steelSteel tube, green compacted and sealed. An explosive pressurePressure pulse yields a dense metallic glass rod. An analysis using X-ray diffraction and scanning electron microscopyElectron microscopy demonstrates that the fully consolidated rod can maintain the amorphous characteristic of the precursors, establishing explosive shockwaveShockwave consolidation as a viable production technique for bulk metallic glasses.

GraphiteGraphite serves as the neutron moderator of British Gas-Cooled Reactors and is a candidate material for the Generation IV of nuclear power stations. The neutron irradiationNeutron irradiation affects the crystalline structure of graphiteGraphite ; this damage results in volumetric changes of the bulk material and generation of porosityPorosity . Dimensional changes induced by irradiation in graphiteGraphite bricks can make difficult the refueling operations and reduce the stability of the graphiteGraphite core. Some of the neutron irradiationNeutron irradiation damage mechanisms in the crystal lattice of graphiteGraphite are not well understood. Results of TEMTEM , SEM, FIB-SEM tomographyFIB-SEM tomography , gas adsorption and optical microscopy will be combined to help understand how the irradiation affects graphiteGraphite at multiple length scales. Furthermore, some new evidence of porosityPorosity and microstructural changes generated by irradiation will be presented.

As the US Light Water Reactor (LWR) fleet ages, irradiation and environmental effects may degrade concreteConcrete structures within the reactor cavity of nuclear power plantsNuclear power plants (NPPs). ConcreteConcrete components provide structural support and serve as a containment barrier and radiation shield. Among the most important constituents of concreteConcrete are the aggregates and cement paste phases. These two phases deteriorate due to different factors, aggregates swell due to the presence of neutron irradiationNeutron irradiation , while the cement may lose water due to gamma-ray-induced hydrolysis. The authors will present a series of results from different characterizationCharacterization techniquesTEM (i.e. TEM, XRD, XRF, EBSDEBSD and ellipsometry) and Fast Fourier Transform (FFT) micro-mechanical simulations using MOSAICMOSAIC that demonstrates the effects of irradiation, moisture, temperature, and constraint on reactor cavity concreteConcrete (RCC). The development of new numerical techniques and understanding of the irradiation effects in concreteConcrete are crucial for the assessment and life extension of the NPPs.

Fe–Cr Alloy/Low-Carbon SteelSteel CompositeComposite was demonstrated in NaClNaCl –KCl–NaF–Cr2O3 molten saltMolten salt system by electrodepositionElectrodeposition method successfully. The electrochemical reaction mechanismMechanism and the electro-crystallization process of chromium in molten saltMolten salt system were investigated by cyclic voltammetry theoretically and by XRD practically. It was found that the electrochemical reduction of Cr(III) takes place in two steps, and the electro-crystallization process of Cr is an instantaneous hemispheroid three-dimensional nucleationNucleation process. Then the optimum preparation conditions, including current waveform and current density, are obtained. And the corrosion resistanceCorrosion Resistance test shows that the corrosion resistanceCorrosion Resistance increases with the increase of Cr content.

Failure of drill collars due to corrosionCorrosion of non-magnetic collar materials is a challenging problem due to corrosionCorrosion . CorrosionCorrosion damages of the drill collars are usually on their internal surfaces due to aggressive mud chemistry (high content of H2S, CO2, dissolved oxygen, pH < 9, etc.) flowing through their annular side. To increase the corrosion resistanceCorrosion Resistance of non-magnetic drill collars, diamond-like carbon (DLC) coatingCoating was applied on long internal surfaces of collars and tested. Roll-bending, fatigueFatigue , erosionErosion and microstructural examinations were performed. Based on encouraging results of laboratory-based studies, field tests were performed. During field test, in HCl acidHCl acid (used to release the collar) condition, challenges were faced. This paper deals with the laboratory test results and challenges faced during field tests. Possible causes of damages of the DLC coatingCoating in HCl acidHCl acid conditions during field tests are also discussed.

Studies on corrosionCorrosion inhibitionInhibition effect of the combined admixture of sage and lavender oil extracts on mild steelMild Steel in dilute H2SO4 and HCl solutions were performed to assess their optimum inhibitionInhibition efficiency at low concentrations through potentiodynamic polarization technique, weight loss analysis and optical image analysis. The surface of the control steelSteel specimen in H2SO4 was subject to severe degradationDegradation , while the steelSteel surface from HCl selectively deteriorated with visible corrosionCorrosion pits. The oil extracts effectively inhibited mild steelMild Steel corrosionCorrosion in both acids with optimal inhibitionInhibition efficiency of 86.92 and 96.90% in H2SO4, and 84.68 and 97.59% in HCl from potentiodynamic polarization and weight loss analysis. Anodic inhibitionInhibition behavior was the dominant inhibitionInhibition mechanismMechanism in H2SO4 resulting from molecular coverage of the steelSteel , and cathodic inhibitionInhibition mechanismMechanism dominated in HCl solution. Thermodynamic calculations showed the extract molecules performed through chemisorption adsorption mechanismMechanism according to Langmuir, Frumkin and Freundlich isotherms.

SteelSteel sheets with three kinds of zincZinc alloy coatings, that is, pure zincZinc coatingCoating , Galfan coatingGalfan coating and Zn–Al–Mg coatingZn–Al–Mg coating , were hot-dippingHot-dipping galvanized by a hot-dip process simulator (HDPS). Alloying elements content as mass percent in the three coatings is Zn–0.2%Al, Zn–5%Al and Zn–2%Al–2%Mg, respectively. Corrosion behaviorCorrosion behavior of the steelSteel sheets with zincZinc -base alloy coatingCoating was studied by total immersion test. Corrosion resistanceCorrosion Resistance of the zincZinc -base alloy coatings dipped with different times was analyzed by means of electrochemical measurement and scanning electron microscope (SEM) analysis. The results show that the Zn–Al–Mg coatingZn–Al–Mg coating has the largest corrosionCorrosion current density at the early stage of immersion. Along with increasing immersing time, corrosionCorrosion current density of the Zn–Al–Mg decreases but that of the pure zincZinc coatingCoating and the Galfan coatingGalfan coating increases. For the Galfan coatingGalfan coating , diffusion characteristics could be found for the Nyquist curve, which means higher corrosionCorrosion rate. However, for the Zn–Al–Mg coatingZn–Al–Mg coating , limited diffusion characteristics could be found for the Nyquist curve, which means corrosionCorrosion product covered the surface enhances the corrosion resistanceCorrosion Resistance .

2101 lean duplex steelDuplex Steel was subjected to extreme temperature of 1200 ℃ and subsequently cooled at rapid and slow rate before assessing its corrosion resistanceCorrosion Resistance in 2 M H2SO4/0%–1.75% NaClNaCl . The annealed steelSteel specimen (A2101ST) corroded at maximum corrosionCorrosion rate of 11.3 mm/y (0.5% NaClNaCl ), trailed by the quenched specimen (Q2101ST). The untreated steelSteel specimen (ASR2101ST) retained it passivity up to 1.75% NaClNaCl . At this concentration, the passive films on Q2101ST and A2101ST collapsed in the presence of the corrosive species. Low surface deterioration occurred on ASR2101ST in comparison to severe intergranular and pittingPitting corrosionCorrosion on Q2101ST. Pseudo-corrosionCorrosion pits formed on the surface of A2101ST.

The present work aims to contribute to a better understanding of the cobalt depositionCobalt deposition onto cobalt and steelSteel through a systematic study of experimental and theoretical potentiodynamic polarization curvesPolarization curves . The occurrence of simultaneous reactions of reduction of hydrogen and oxygen was taken into account. The possibility of galvanic deposition was also investigated. Experimental curves were constructed from tests using cobalt and carbon steelSteel working electrodes in electrochemical cells with electrolytes containing cobalt ions and boric acid with and without nitrogen injection. Theoretical curvesTheoretical curves were constructed based on the individual redox reactions for the considered system. For each of the reactions, the Butler–Volmer equationButler–Volmer equation was analyzed, considering the occurrence of concentration polarization. By comparing the theoretical and experimental curves, a quantitative approach of the cobalt depositionCobalt deposition on a cobalt electrode could be established. The analysis of theoretical curvesTheoretical curves for cobalt depositionCobalt deposition on a steelSteel electrode allowed a qualitative comparison with the experimentally obtained curves.

The control of nanostructures and miniaturization in advanced industries is one of the priorities of the modern industry. MicrostructureMicrostructure , during sintering and grain growthGrain growth processes, is affected by some factors such as temperature, time, rate of heating, pressurePressure , and the atmosphere. In this paper, a method in which nanostructure can be engineered is described, and grain growthGrain growth is explained by the self-similar coarsening of the microstructureMicrostructure . In simulationSimulation of grain growthGrain growth , ABO3 structure was employed in atomic scale, with regard to not only different radii of atoms but also different orientations of grains. To run simulationSimulation , initial parameters were firstly selected, including seed numbers, atomic radii, coefficient of seed production, sintering temperature and time; an incentive for atomic diffusion coefficientDiffusion coefficient was additionally chosen. Fractal dimensionFractal dimension of real and simulated images can set our machine to find final structure.

In this paper, different nucleationNucleation mechanisms of AlN in ML40CrML40Cr steelSteel austenite phase were systematically analyzed through theoretical calculations. According to the calculation results and analysis, the critical nucleationNucleation size of the AlN precipitationsPrecipitations in the ML40CrML40Cr steelSteel decreases with the decrease of the temperature under the three different nucleationNucleation mechanisms. The critical nucleationNucleation sizes range from 0.5 to 6 nm. The “nose temperature” which means the fastest precipitationPrecipitation temperature at uniform nucleationNucleation , grain boundary nucleationNucleation and dislocation nucleationNucleation PTT curves of AlN precipitationsPrecipitations in ML40CrML40Cr austenite phase is 810, 1090, 870 °C. When the temperature is lower than 880 °C, the nucleation mechanismNucleation mechanism of AlN in ML40CrML40Cr steelSteel austenite phase is dominated by grain boundary nucleationNucleation and dislocation nucleationNucleation . When the temperature is higher than 880 °C, the nucleation mechanismNucleation mechanism of AlN is dominated by grain boundary nucleationNucleation .

The melt flow can significantly change the dendrite morphology during alloy solidificationSolidification . The modelingModeling and simulationSimulation of dendrite growthDendrite growth under melt flow is vital for predicting and controlling the superalloySuperalloy solidificationSolidification microstructureMicrostructure . In this work, the multiphase-fieldMultiphase-field model was employed to simulate superalloySuperalloy dendrite growthDendrite growth , and the lattice Boltzmann method was used to solve the fluid flow problem. The commercial Pandat database was used to present realistic multicomponentMulticomponent superalloySuperalloy thermodynamic data in multiphase-fieldMultiphase-field model. In single dendrite growthDendrite growth , zero and nonzero inlet velocities were applied to investigate the effects of forced convectionForced convection on dendrite morphology. In multi-dendrite solidificationSolidification , the dendrite morphology, fraction solid and average fluid velocity were obtained and analyzed.

The paper describes how a simplified adoption of the Maximum Entropy Production Principle (MEPP) enables the modelingModeling of volume diffusion-controlledDiffusion-controlled multiphaseMultiphase multicomponentMulticomponent alloy systems with no assumption about interface conditions. NucleationNucleation and dissolutionDissolution have been added to the treatment. A short review of the mathematics behind solving the second-order parabolic partial differential equation describing diffusion gives the degrees of freedom available for modelingModeling sharp interfaceSharp interface moving boundaryMoving boundary problems appearing in phase transformationPhase transformation treatments. It is then discussed how volume diffusion-controlledDiffusion-controlled phase transformations can be modelled by referring to MEPP. Finally, it is outlined how multiphaseMultiphase , multicomponentMulticomponent systems can be approximated while still retaining some of its major behavior. Application of this approximative treatment is exemplified by sigma phaseSigma phase precipitationPrecipitation , growth and dissolutionDissolution in a duplex stainless steelStainless steel.

The activities of components of Au–Cu alloyAu–Cu alloy were calculated using the simplified molecular interaction volume model (SMIVMSMIVM ). The calculated average relative deviation Si and average standard deviation Si* are smaller than ±0.5528% and ±0.0100, respectively, which indicates that the calculation of the activities of Au–Cu alloyAu–Cu alloy by SMIVMSMIVM is reliable. The VLEVLE data of Au–Cu alloyAu–Cu alloy were calculated based on the VLEVLE theory and the SMIVMSMIVM . The VLE phase diagrams (i.e., T − x(y) and p − x(y)) of Au–Cu alloyAu–Cu alloy were also established in this work. The VLEVLE phase diagrams offer an intuitive and simple way to analyze the product compositions’ dependence of temperature and system pressurePressure in vacuum distillation, which also provide an effective way of determining the optimum technique parameters. This has important guiding significance for efficient separation of alloys by vacuum distillation.

Millerite (NiS) as the important source for nickelNickel extraction has been investigated by density functional theory calculations to study the surface oxidationSurface oxidation mechanismMechanism . Atomic oxygen adsorption and molecular oxygen adsorption on the (001) surface of millerite have been performed. For atomic oxygen adsorption, the results reveal that nickelNickel hollowHollow site is more favored with more negative adsorption energyEnergy compared to the nickelNickel top site. Mulliken charge analysisCharge analysis indicates that there are more electrons transferred from the nickelNickel atoms to the oxygen atom at the hollowHollow site. For molecular oxygen adsorption on the (001) surface of millerite, the parallel adsorption site was found to be more favorable than vertical adsorption site with more negative adsorption energyEnergy . And the dissociative adsorption of O2 leads to more negative adsorption energyEnergy , indicating that the oxygen can easily undergo dissociation on millerite surface.

In order to promote the development of the direct fiber-forming process of blast furnaceFurnace slagSlag , utilize the sensible heat of the blast furnaceFurnace slagSlag and reduce environmental pollution, the dissolutionDissolution rate of silica particles in CaO–SiO2–MgOMgO –Al2O3 slagSlag system was measured, and a kinetic modelKinetic model for describing the dissolutionDissolution process of silica was established using the macro-kinetic principle. The results show that under the experimental conditions, the dissolutionDissolution process of silica in CaO–SiO2–MgOMgO –Al2O3 slagSlag system is controlled by its surface dissolutionDissolution reaction, and the reaction temperatureTemperature has a significant influence on the rate constant of SiO2SiO2 dissolutionDissolution reaction. The calculated dissolutionDissolution activation energyActivation energy is 524.52 kJ/ mol. With the increase of reaction temperatureTemperature , the dissolutionDissolution rate of silica in slagSlag increases.

Heat-resistant FeCrNi alloysFeCrNi alloys are widely used in the petrochemical industry because they exhibit a unique combination of creepCreep and oxidation resistance at temperatures exceeding 900 °C. Their creepCreep properties are often optimized by micro-additions of carbide-forming elements. In the present work, the influence of Ta micro-additions has been experimentally investigated both on as-cast and aged microstructures to understand the origin of the significant impact of this element on the creepCreep resistance. Calculations with Thermo-Calc software were also carried out to support experimental data. It is shown that a small addition of Ta is beneficial as it increases the volume fraction of stable MC carbidesCarbides . We demonstrate also that additions of Ta may have a dramatic effect on the thermal stability of microstructures. This is attributed to a smaller equilibrium volume fraction of M23C6 and more pronounced heterogeneous precipitationPrecipitation at MC/matrix interfaces. The influence on the creepCreep properties is then discussed.

A large amount of damaged W-shaped radiant tubeW-shaped radiant tube in cold rollingCold rolling continuous annealingAnnealing line has been found in Shougang Jingtang Company in recent years. After excluding harmful element erosionErosion by element analysis, the finite elementFinite element method was utilized to study the installation structureInstallation structure on the stress field of radiant tube. The results show that the improper installation is the direct reason for cracking and damage of radiant tube, and then the optimization scheme for improving the installation structureInstallation structure of radiant tube is further proposed. The maximum equivalent stress of radiant tube at 850 °C is about 104 MPa after optimization, and there is no large local stress concentration. The damage probability of radiant tube is greatly reduced base on this optimization, and the service life of radiant tube is extended from 2 to 5 years.

The continuous improvementContinuous improvement methodology of six sigma and lean include methods such as 6s team projects, kaizen events, recommissioning projects, and Gemba walks. These are useful in all industries but are critical in the materials industry. This paper gives case studies from several projects emphasizing energy savingsEnergy savings and melt lossMelt loss from the secondary aluminumAluminum and casting industries. Some projects worked well while others fell short due to specific issues. The example projects and their issues will be discussed. Measurement problems will be reviewed. Some data analysis can be different with energyEnergy data in the metals industry. These analysis concerns will be discussed.

Many independent spent fuel storage installations (ISFSI) are located along the coastal regions in the US and the dry storage canisters consisting of spent nuclear fuels are envisioned to undergo chloride-induced stress corrosionCorrosion cracking (SCCSCC ) in heat-affected zoneHeat-affected zone (HAZ) . In the present study, we have investigated SCCSCC behavior of sensitized SS304H under substitute ocean water at room temperature using wedge opening loading (WOL) specimens. The alloy was sensitized at 600 °C for 215 h followed by microstructural characterizationCharacterization . The crack growth during the test was monitored using direct current potential dropPotential drop technique. The crack growthCrack growth rate for the SS304H alloy was within the same order of magnitude as reported in literature for SS304 alloy under chloride environment.

Two welds on a primary process piping in a hydrocracker unit leaked after 2 years in service. Dye penetrant and magnetic particle inspection of the two tube–flange joints indicated circumferential cracking. The first connection was a similar metal weld (SMW)Similar metal weld (SMW) with ferritic steelSteel materials. The second leak was at a dissimilar metal weld (DMW)Dissimilar metal weld (DMW) , with a ferritic steelSteel tube welded to a 321 stainless steelStainless steel (SS) flange. These lines were exposed to a stream consisting of 84 mol% H2, 0.85 mol% H2S, 0.15 mol% H2O (balance hydrocarbon) operating at 123 bar and 248 °C. Following metallography and SEM analysis, it was determined that the SMWSimilar metal weld (SMW) failed due to inadequate welding procedures that promoted high hardnessHardness and rendered the material highly susceptible to cracking. The DMWDissimilar metal weld (DMW) failed due to inadequate fit up and wrong filler metal selection, which led to development of hard zones in the weld deposit. Adequate pre- and post-weld heat treatmentAnd post-weld heat treatment (PWHT) for SMWSimilar metal weld (SMW) joints, and weld design modifications and positive material identification (PMI) inspection for DMWDissimilar metal weld (DMW) joints, were recommended.

In this study, precipitationPrecipitation behavior with different vanadium contents before and after temperingTempering process and their effects on hydrogen diffusion and hydrogen-induced plastic loss were investigated in high-vanadium hot-rolled X80 pipeline steelSteel . The results showed that the microstructureMicrostructure transformed from lath bainite, ferrite to granular bainite, massive ferrite and a small amount of M/A constituents after temperingTempering treatment. Besides, the number of nanoscale precipitates obviously increased. These fine precipitates can fix a large amount of diffusible H atoms as traps and reduce the damage of hydrogen. The hydrogen diffusion coefficientDiffusion coefficient in as-tempered sample decreased using hydrogen permeation test. Moreover, after temperingTempering treatment, the dislocation densityDislocation density distinctly decreased, which significantly improved the resistance to hydrogen-induced ductility lossHydrogen-induced ductility loss .

Experimental evidence concerning the mechanismMechanism of initiation and early growth of short cracks are studied using FESEM, FIB and STEM observations of the surface of fatigued specimens of several f.c.c. metals. The true shape of persistent slip markingsSlip markings with high resolution is obtained on FIB cuts and using lamella milled on the surface. Thick extrusions and parallel thin crack-like intrusionsIntrusions are typical feature before crack initiates from the tip of the intrusion. STEM also reveals the relation of the surface relief and internal structure of the material showing in copperCopper ladder-like dislocation structure. The shape of the persistent slip markingsSlip markings is confronted with the predictions of the recent theoretical models. Study of the short crack growthCrack growth and its kineticsKinetics shows high density of initiated surface cracks and proves the acceleration of the crack growthCrack growth rate due to linkage of principal crack with initiated surface cracks. Fatigue lifeFatigue life is determined by the growth of short cracks and short crack growthCrack growth law is equivalent to the Manson–Coffin law.

The production of synthetic tantalumTantalum concentrate (SynCon) from process residues, sludges or tin slags generates huge amounts of high meltingMelting slagSlag , mostly comprising of Al2O3, CaO and SiO2SiO2 . The metal/slagSlag separation is a major criterion in the multi-stage pyrometallurgical procedure to ensure product quality and yield, wherefore the flow properties of respective slags depict essential preconditions. Hot stage microscopeHot stage microscope tests are performed to investigate the melting behaviourMelting behaviour of synthetic SynCon slags under process near conditions (temperature range of 1000–1600 °C and reducing as well as inert atmosphere by usage of CO/CO2 and Ar gas). Sample analyses via REM/EDX and measured flow temperatures are compared to thermodynamic calculations conducted with FactSage 7.1 to enhance process control and to obtain first conceptions on the meltingMelting range and the slagSlag viscosity, which are influenced by slagSlag composition and temperature.

The ISASMELT™ISASMELT™ top submerged lance (TSLTSL ) furnaceFurnace is set apart from other smeltingSmelting technologies due to the flexibility of the reactor to be designed with a wide range of lining systems, from pure refractory linings to intensively cooled systems. The turbulence of the molten bath generated by the submerged gas injection allows for the slagSlag in the furnaceFurnace to be held in constant turbulent equilibrium at a lower thermal set point, when compared to other smeltingSmelting furnaceFurnace technologies. Such operation promotes freeze linings to form in both refractory-only and cooled-element type systems. This paper reviews ISASMELT™ISASMELT™ plant campaign performance and how various sites use this to optimise their process, operation and economics.

In 2016, a 63 MVA sub-merged arc furnace producing ferrochrome in South Africa was shut down and partially excavated for partial repair of its refractory lining as part of the annual maintenance activities. No significant evidence of the formation of a freeze-liningFreeze-lining was found, although the lining design philosophy applied was of the conductive type typically applied. The paper presented here, investigate the possibility that the slagSlag practice applied prior to excavationExcavation was not conducive to the formation and maintenance of a stable freeze-liningFreeze-lining . The study included identification of the slagSlag regimes under which the SAF was operated in the 12 months prior to the excavationExcavation , using data science techniques, and studying the effect of different regimes on freeze-liningFreeze-lining behaviour, using transient one-dimensional heat transferHeat transfer and thermodynamic models. Where available, temperature dependent properties for slagSlag and refractory were utilised in the heat transferHeat transfer calculations.

The formation of a freeze liningFreeze lining on the hot face of furnaceFurnace sidewalls to increase campaign life is an accepted concept in industry today. This is achieved through a well-engineered sidewall cooling system typically consisting of cooled copperCopper elements, either on their own or in combination with a refractory lining. The design of the lining/cooling system to form and maintain a competent freeze liningFreeze lining is discussed. Heat losses under normal operating conditions are calculated as an input to the furnaceFurnace energyEnergy balance. The lining/cooling system is evaluated under extreme operating conditions as this ultimately determines campaign life. Variables to be evaluated include freeze liningFreeze lining thicknessThickness and formation rate, copperCopper element temperatures, cooling medium used, and required cooling density and arrangement. Steady-state and transient thermal FEA are used as tools to evaluate the lining/cooling system design.

A comparative research on the characteristics and corrosion resistanceCorrosion Resistance of two kinds of hot dipping alloy coatingCoating section for 55%Al–43.5%Zn–1.5%Si and Zn–11%Al–3%Mg–0.2%Si. The distribution and organization of the cross-sectional elements were analyzed by glow discharge apparatus and metallurgical microscope. And electrochemical workstation was applied to test Tafel polarization curvesPolarization curves and electrochemical impedance spectroscopy. The results showed that 55% zincZinc Al–43.5%–Si alloy coatingCoating surface was mainly Al and Zn, near the inner side main ingredients for Fe, Al, and the corrosionCorrosion potential of 1050.7 mV; Zn–11%Al–3%Mg–0.2%Si alloy coatingCoating surface composition was mainly Zn, Al, Mg, and close to the inside the main components is Fe, Zn, the corrosionCorrosion potential of −710.7 mV. The corrosion resistanceCorrosion Resistance of 55%Al–43.5%Zn–1.5%Si alloy coatingCoating was significantly better than the Zn–11%Al—3%Mg–0.2%Si coatingCoating .

In this study, pylonPylon section of lower limb prosthetic device was fabricated by additive manufacturingAdditive manufacturing technique. Polylactic acidPolylactic acid polymer was used as the filament for 3D printing3D printing of pylons. The 3D printed pylons were tested to evaluate their compliance with the standards set by ISO 1038:2016 (Prosthetics—Structural testing of lower limb prostheses—Requirements and test methods). A static proof test and compression test were applied on the pylons to evaluate their performance. The results showed that 3D printed pylons have enough strengthStrength under stress and exceed the requirements of the standards and therefore can replace the metallic pylons in lower limb prostheses. Using 3D printers as an alternative fabrication technique can open a new horizon to increase the accessibility of lower limb prostheses for low-income populations.

AOD slagAOD slag was employed as main raw material, and cement clinker was added into AOD slagAOD slag to prepare compositeComposite cementitious materialCementitious material . The obtained material was subjected to sequential leaching experiment to illustrate the influence of particle size, liquid–solid ratio, initial pH of leaching solution on leaching characteristics of chromium from cementitious materialCementitious material . The results indicated that the fine particle size of the cementitious materialCementitious material has a positive effect on the dissolutionDissolution of the chromium-bearing mineral, thereby increasing the chromium concentration in the leaching solution. When the liquid–solid ratio was increased from 10:1 to 20:1 and 100:1, the chromium concentration in the leaching solution did not decrease proportionally with the increase of the liquid–solid ratio. The strong acidic and weak alkaline leaching solution possessed a great influence on the dissolutionDissolution concentration of Cr6+ in the cementitious materialCementitious material , and the leaching riskLeaching risk of chromium cannot be ignored.

The hydrochloric acid leachingHydrochloric acid leaching process of titanium-containing blast furnace slagTitanium-containing blast furnace slag was studied. The results showed that the optimal experimental conditions for the leaching reaction of hydrochloric acid were liquid-to-solid ratio 10:1, heating temperature 100 °C, hydrochloric acid concentration 7%, raw material particle size 150–250 μm, and reaction time 6 h. The factors affecting the leaching reaction from descending to large are HCl concentration > reaction time > heating temperature > slagSlag particle size T.

A thermodynamic modelThermodynamic model of (NbxTivVz) (CyN1−y) was established based on sub-lattice model. The molar fraction, atom ratio and precipitationPrecipitation regularity in solute-rich regionsSolute-rich regions and solute-depleted regionsSolute-depleted regions of Ti–Nb–V bearing steelSteel in the temperature range from 1023 to 1623 K were also calculated by the model. The size of precipitationsPrecipitations was calculated by dynamic model. The calculation results were verified by the experiment using transmission electron microscopyElectron microscopy (TEM)TEM and energyEnergy dispersive spectroscopy (EDS). The investigation indicated that the type of precipitationsPrecipitations in solute-rich regionsSolute-rich regions and solute-depleted regionsSolute-depleted regions was Nb0.039V0.001Ti0.96N, and their corresponding sizes of precipitationsPrecipitations are 90–130 nm, 50–90 nm, respectively. Nb (CN) in solute-rich regionsSolute-rich regions and solute-depleted regionsSolute-depleted regions precipitated in the temperature range 1523–1223 K, and their corresponding sizes of precipitationsPrecipitations are 27–50 nm, 9–20 nm, respectively. VC started to precipitate at 1124 K, 1073 K, respectively, in the solute-rich regionsSolute-rich regions and solute-depleted regionsSolute-depleted regions , the size of particles is 7–9 nm, changed unobviously in solute-rich regionsSolute-rich regions and solute-depleted regionsSolute-depleted regions .

A rotationally accelerated shot peening (RASP) technique was used to improve the radiation and corrosionCorrosion resistances of 316LN austenitic stainless steelAustenitic stainless steel (316LN SS). The experimental results indicated that high density nanoscale twin boundaries (NTBs) were introduced in the steelSteel after the RASP. These boundaries were found not only beneficial to enhance radiation resistance but improve the corrosion resistanceCorrosion Resistance of the steelSteel . Radiation experiments showed the average size of helium bubbles and unstable shear bands were restrained in the RASPed 316LN SS comparing to those tested in the as-received 316LN SS samples. The electrochemical test results revealed the critical pittingPitting potential and passive film resistance value of the steelSteel increased after treated by the RASP. These results shed light on radiation and corrosionCorrosion resistances robust developments in advanced nuclear materials.

A novel dual-phase gradient material of a high-entropy alloyHigh-entropy alloy (HEA) FeCoCrNiMo0.15 was fabricated by spark plasma sinteringSpark plasma sintering (SPS) processing. After SPS, the HEA specimens consisted of a single face-centred cubic (FCC) phase in the centre but dual FCC and body-centred cubic (BCC) structures near the surface. Surprisingly, the sintering pressurePressure was sufficient to influence the proportion of phases, and thus, the properties of HEA samples. The hardnessHardness of the specimen sintered under a pressurePressure of 30 MPa increased gradually from 167 HV in the centre to 634 HV near the surface due to the gradual increase in the fraction of the transformed BCC phase. This phase transformationPhase transformation , which could be influenced by pressurePressure indicated a major possibility for designing gradient HEA materials.

Molecular dynamics simulationsMolecular dynamics simulations were employed to investigate the plastic deformation of AlCoCrCu0.5FeNiAlCoCrCu0.5FeNi high-entropy alloyHigh-entropy alloy (HEA) nanopillars with a body-centered cubic structure. The plastic deformation of HEA and pure Fe nanopillars was observed to be dominated by deformation twinningDeformation twinning . However, the yield stress of the HEA nanopillars is smaller than that in pure Fe nanopillars. The generalized stacking faults energyEnergy (GSFE) and generalized planar fault energyEnergy (GPFE) were calculated, which suggest that the $$ {\text{a}}/6\,\;\left\langle {111} \right\rangle \, $$ twinning dislocations are more likely to nucleate than $$ {\text{a}}/2\,\;\left\langle {111} \right\rangle \, $$ full dislocations. The emission of $$ {\text{a}}/6\,\;\left\langle {111} \right\rangle \, $$ twinning dislocations on adjacent {112} slip planes is also much easier than that of $$ {\text{a}}/2\,\;\left\langle {111} \right\rangle \, $$ full dislocation on the same {112} slip plane. Hence, it can be concluded that deformation twinningDeformation twinning is the favorable plastic deformation mode in HEA nanopillars at room temperature, and alloying elements facilitate the nucleationNucleation of twins.

In this study, high-entropy alloysHigh-entropy alloys of AlCoCrFeNiME (ME = B, Cu, Ti) were produced by a self-propagating high-temperature synthesisSelf-propagating High-Temperature Synthesis (SHS) starting from metal oxide powder mixtures. The effects of the grain size and initial weight of raw materials with the ratios of the metal oxides on metal recovery values and properties of the final alloys were investigated. The final products were characterized by using XRD, optic microscope and SEM/EDS techniques.

Six years ago, Materials Science and Engineering at Michigan Tech embarked on a quest to integrate ICMEICME into the undergraduateUndergraduate curriculum. It began with small modules within a “methods” course that preceded the 2-semester capstoneCapstone project course. A holistic strategy gradually evolved over the next several years, culminating in a “Material Design” course the spring of junior year followed by industry-sponsored senior projects scoped to utilize ICMEICME methods. The Material Design course combines experimental measurements with measurement system analysis (MSA), thermodynamic and kinetic material optimization with the design of experiments (DOE), and an overarching material design project. The course is organized with weekly module themes that require prereading, lab/modelingModeling work and reports, and a Friday practical quiz. Along the way, students learn to keep a notebook, use Thermo-Calc and Minitab, and write a comprehensive report. All of the skills developed in “Material Design” are to be applied in the capstoneCapstone project course the following semester.

Twin boundaryTwin boundary (TB) as a perfectly symmetric grain boundary has received lots of attention for the positive effects on material strengthStrength and ductility. A bicrystal containing a vertical TB was introduced in discrete dislocation dynamicsDislocation dynamics (DDD) method to study the effect of TB on the mechanical propertyMechanical property . The DDD results show that the TB has hardly any hardening or softening effect on the strengthStrength and sample size effects of bicrystals, as compared with the single crystals. This is because the deformation is mainly mediated by screw dislocations, which are able to pass through TB in a cross-slip-like manner without any blocking effect from TB.

The long-term dipping corrosionCorrosion experiments were performed on Haynes 230Haynes 230 (H230) in molten eutectic MgCl2-KClMgCl2-KCl at 973 K with and without connection with Ni-201 alloy. The results showed that the corrosionCorrosion rate of H230 was 1.62 mg/cm2/day while connecting with Ni-201 alloy. However, for the H230 which was not connecting with Ni-201 alloy, the corrosionCorrosion rate was 0.95 mg/cm2/day. Therefore, Ni-201 alloy accelerates the corrosionCorrosion rate of H230 in the molten MgCl2-KClMgCl2-KCl salt while connecting to each other. For the analysis of SEM-EDS, W deposition was found on the connected Ni-201 alloy. However, no deposition was shown on the surface of the Ni-201 alloy which was not connected with H230. In addition, based on the SEM-EDS and ICP-OESICP-OES , the weight of dissolved elements in salt is in good agreements with weight loss of samples.

This work is dedicated to the mechanical testing of the materials used for the nuclear plants applicationsApplications in the hot cellsHot cells facility built in Czech Republic. The variety of mechanical tests performed in the Research Center Rez, Ltd., is described. Namely, an experimental work on the irradiated A533 pressurePressure vessel steelSteel and mechanical behaviorMechanical behavior of Cr-Ni-Ti steelSteel in the corrosive environment at elevated temperatures are presented. The evolution of the hot cellsHot cells from the construction to the active mechanical testing of the irradiated materialsIrradiated materials is described.

Nuclear structural materials subjected to neutron irradiationNeutron irradiation accumulate dose-dependent, disperse defect clusters populations. Subsequent dislocation/defect interactions induce material mechanical propertyMechanical property degradations, including hardening and embrittlement. Our goal in this work is to evaluate the effect of disperse defect clusters population on the effective dislocation mobility in ferritic Fe–Cr grains, using 3D dislocation dynamicsDislocation dynamics simulations. The defect-induced changes of the grain-scale mechanical response are evaluated using the recently proposed Defect-Induced Apparent Temperature (DIAT) shift concept. It is found that the DIAT shiftDIAT shift associated with a given defect dispersion scales with the ductile to brittle transition temperature (DBTT) shift associated with exactly the same, observed defect population. The dose-dependent evolutions associated with broad irradiation temperature and straining temperature changes are investigated herein, for further exploration and validation of the DIAT shiftDIAT shift concept.

The compression of amorphous siliconAmorphous silicon nanoparticlesNanoparticles is investigated by means of molecular dynamics simulationsMolecular dynamics simulations , at two temperatures and for diameters equal to 16 and 34 nm. The nanoparticlesNanoparticles deform plastically, with maximum contact stresses in the range 8.5–11 GPa, corresponding to strains between 12 and 24%. No clear size effect is observed. Despite large contact stress values, the formation of high-density crystalline or amorphous phases is not observed, presumably due to the presence of lateral free surfaces allowing for plasticityPlasticity deconfinement. Atomic displacements analysis confirms that during plastic deformation, atoms close to indenters are first pushed towards the nanoparticle center, before migrating laterally towards free surfaces. Plastic deformation leads to an increase of fivefold coordinated atoms, which are spatially correlated with the largest atomic displacements.

The structure and transport properties of xKF–yNaF–zAlF3 molten saltMolten salt are studied by molecular dynamicsMolecular dynamics simulationSimulation , from which a deep understanding of the subjects and their interactions are gained at the level of molecular. The calculated results show that the local ions in the xKF–yNaF–zAlF3 molten saltMolten salt system still maintain the short-range and ordering structure of five-coordinated [AlF5]2− and six-coordinated [AlF6]3− with [AlF5]2− aluminumAluminum fluoride complex ion being the main form of aluminumAluminum ion in molten saltMolten salt . With the concentration of KFKF increasing in the molten saltMolten salt , the diffusion capacity of Na+ and F− ions have been improved, and the degree of polymerizationDegree of polymerization of the system has been effectively reduced, which indicates that K+ can promote the movement of Na+ and F− in the molten.

The low silver copperCopper alloy (LSCA) wires characterized by high electrical and high mechanical propertiesMechanical properties was prepared by in situ compositeIn-situ composite technology. In this work, the evolution of microstructureMicrostructure and properties of the LSCA from rod to wires were studied. The LSCA (Cu–1.0 wt%Ag)with the diameter of 30 mm was prepared and then solid solution treated at 800 °C for 4 h. Then, the ingot was rolled and drawn to wires with the diameter of 3.00 mm aged at 500 °C for 4 h. The microstructureMicrostructure of specimen in different states were investigated and the sequent conductivity and mechanical propertiesMechanical properties were also studied.

Although most studies have been concentrated on the quasi-static performance of alpha+beta titanium alloys, the dynamic performance of them especially in the intermediate regime is in its infancy. In this study, we conducted different rapid heating and cooling treatments (RHCT) on TIMETAL 64 (alpha+beta, 6 Al, 4 V) and TIMETAL 639 (alpha+beta, 6.5 Al, 1.7 Mo, 1.7 V, 0.3 Si). The resulting microstructure was characterized using electron backscattered diffraction (EBSD) before and after the RHCT process. To correlate the effect of proposed RHCT on the quasi-static (10-3/s), and intermediate (100/s) behavior of the heat-treated samples, we utilized the compression and split Hopkinson pressure bar (SHPB) tests, respectively, to compress the specimens. Results have demonstrated that the dynamic ductility of the TIMETAL 639 outperforms the one of the TIMETAL 64, attributed to the bimodal microstructure of the TIMETAL 639.

A medium-carbon steelMedium-carbon steel with different silicon content was studied by dilatometric analysis during continuous heatingContinuous heating . The critical transformation temperatures were determined from the dilatometric curves and linear regression method, applied to the dilatometric behavior and the first derivative as a function of temperature. It was observed that when increasing the silicon content, the dilatometric behavior tends to be similar as a low-carbon steelSteel with the presence of two peaks; the first, associated with the decomposition of pearlite and the second to the austenite formation from pro-eutectoid ferrite, in the last, there was a noticeable delay in the transformation. The transformation rate was calculated employing the Johnson-Mehl-Avrami-Kolgomorov rate model and the Kissinger method was used to estimate the activation energyActivation energy for each stage depending on the heating rate and the composition. Finally, a hard effect of silicon on the austenite formation was shown, especially in the second transformation stage and activation energies.

IntermetallicIntermetallic phase precipitationPrecipitation is of great interest for designing novel nanostructured high-strengthStrength alloys. In this study, phase-fieldPhase-field simulations were employed to simulate the microstructure evolutionMicrostructure evolution and elemental distribution during the nano-sized Fe3AlC intermetallicIntermetallic phase precipitationPrecipitation within the austenite matrix in a lightweight high-strengthStrength steelSteel . The phase-fieldPhase-field simulations were carried out in a two-dimensional rectangular domain of 200 × 200 cells with an ultra-fine grid spacing of 2 nm to simulate the nano-sized intermetallicIntermetallic phase precipitationPrecipitation at 800 °C. The elemental redistribution and the partitioning characteristics in the material were further studied experimentally by atom probe tomography. The simulated results were compared with the experimental data. The results show that during the κ-phase precipitationPrecipitation , the C and Al atoms are highly enriched in the κ-phase precipitates, while the Ni and Mn are depleted in the κ-phase precipitates. The elemental redistribution and partitioning features, i.e. Al, C, Mn, Ni, during the intermetallicIntermetallic phase precipitationPrecipitation in the steelSteel was further discussed.

Due to their high actuation energyEnergy density and ability to sustain large deformations, shape memory alloysShape memory alloys (SMAsSMAs ) have many potential engineering applicationsApplications , such as solid-state actuation, energyEnergy damping, and shape recovery upon deployment. While SMAsSMAs have been studied extensively since the discovery of NiTiNOL in 1959, the effects of restricting the reversible martensitic transformation to nanodomains is not well-understood and is yet to be utilized in engineering applicationsApplications , despite showing promising multifunctional properties. In binary NiTi, the martensitic transformation, characterized by long-range strain ordering, can be replaced with a strain glassStrain glass transition. Such alloys have been named strain glass alloysStrain glass alloys (SGAs) due to the fact that they exhibit a glass-like state which is caused by compositionally- or processing-induced strain. In the present study, cold work is used to produce a strain glassStrain glass phase in bulk, Ti-rich NiTi specimens, and their bulk shape recovery properties are analyzed. In addition to showing reduced dimensional instability as well as increased energyEnergy density, the processing-induced SGA shows an order of magnitude less strain localization relative to the SMA material system from which it was developed. For this research, bulk thermomechanical testing, digital image correlation (DIC), differential scanning calorimetryDSC (DSC), synchrotron X-ray diffraction (SR-XRD), and transmission electron microscopyElectron microscopy (TEM)TEM were utilized to characterize a processing-induced SGA which was developed from commercially available Ni49.5Ti50.5 (at.%).

Al–Sc–Zr alloys have the potential for elevated-temperature strengthStrength resulting from thermally-stable $$ {\text{L}}1_{2} $$ precipitates. However, low solubilities of Sc and Zr limit precipitate volume fractions, enabling dislocation bypass via climb. One method to increase precipitate volume fraction involves using rapid cooling techniques to increase supersaturation. Rapid cooling utilizing melt spinning ( $$ 10^{7} $$ k/s) can increase solute supersaturation by a factor of ~8 from Al–0.06Sc–0.06Zr at.% to Al–0.5Sc–0.4Zr at.%. Melt-spun ribbon underwent isochronal heat treatmentHeat treatment . The ambient temperature hardnessHardness of peak-aged ribbon increased over the aged Al–0.06Sc–0.06Zr at.% by 450 MPa (67%).

The influence of equilibrium solidificationEquilibrium solidification and rapid quenchingRapid quenching on element segregationSegregation and effect of Sm contentSm content on phase composition and microstructureMicrostructure of SmFe alloy ribbons were systematically investigated. Rapid quenchingRapid quenching treatment is beneficial to homogenizing the distribution of material components, reducing the elements segregationSegregation , and inhibiting the formation of ɑ–Fe phase. When the Sm contentSm content is high (~30%), the ribbon is mainly composed of Sm2Fe17 phase and Sm-rich phase which is distributed at the boundary of Sm2Fe17 grain in spherical or irregular shapes, and the amorphous content increases with the improvement of rapid quenchingRapid quenching speed. When the Sm contentSm content is low (~24%), the ribbon is mainly composed of Sm2Fe17 phase and ɑ–Fe phase. It can be seen from the ratio of the strongest peak of I(303)/Iɑ–Fe, with the increase of rapid quenchingRapid quenching speed, the Sm volatilizes and results in the content of ɑ–Fe increases.

The aim of the paper is to investigate the effect of hot-top pulsed magneto oscillation (HPMO)Hot-top pulsed magneto oscillation (HPMO) on the microstructureMicrostructure and dendritic morphologyDendritic morphology of solidified structure in ingot casting. The experiment indicates that the dendrites located in the center of ingot can be completely changed from dendritic crystals into granular equiaxed crystals, the dendrites located in the 1/2-radius area of ingot can be changed from coarse dendritic crystals into tiny equiaxed crystals that after HPMOHot-top pulsed magneto oscillation (HPMO) treatment. Further, applying the HPMOHot-top pulsed magneto oscillation (HPMO) technology in the solidificationSolidification process of the ingot under slow-cooling can refine the solidificationSolidification structure and change the solidified microstructureSolidified microstructure morphology from dendritic into equiaxed. It is also proved that the prospect of applying the HPMOHot-top pulsed magneto oscillation (HPMO) technology to improve the ingot quality in industrial mold casting is very promising.

The δ ↔ γ phase transformationPhase transformation in duplex stainless steelStainless steel (DSS) was observed by Ultra High TemperatureHigh temperature Confocal Laser Scanning Microscope (UHT-CLSM). It is shown that the γ → δ phase transformationPhase transformation preferentially occurs near the spherical precipitates. Then the δ-ferriteδ-ferrite phase transformationPhase transformation happens in the form of “explosion” and extends to the whole surface at 1100 °C. According to the meltingMelting and solidificationSolidification model of the DSS, the migration rate of incoherent boundariesIncoherent boundaries and semi-coherent boundariesSemi-coherent boundaries into the matrix are 0.463 μm/s and 0.315 μm/s, respectively. The δ-ferriteδ-ferrite grain preferentially melts at the incoherent δ-ferriteδ-ferrite grain boundaries (GBs) which have higher energyEnergy . After 5 s, the meltingMelting occurs at the semi-coherent boundaries and inner grains. During the solidificationSolidification , the δ ferrite appears first at the original austenite GBs and grows along the δ/δ boundaries. The migration of δ/δ boundaries leads to the refinement of δ ferrite and the δ → γ phase transformationPhase transformation at grain boundaries when the temperature is 1075 °C. Besides, the synergistic action of the precipitates makes the growth rate of γ-austenite faster than other locations.

Depending on the physical circumstances, two nuclei might not form very close to one another. That is, there might be an exclusion zone around each nucleus. Formal treatments of nucleationNucleation and growth transformations normally suppose that nuclei are located uniform randomly, i.e. according to a Poisson point process, within the matrix. In this work, we model nuclei location in space using the so-called Sequential point process. The Sequential point process can produce a range of nuclei arrangements in space in which each nucleus possesses an exclusion radius. Computer simulations of transformations with these nuclei arrangements are compared with a transformation nucleated according to the usual Poisson point process. The resulting microstructural evolution is characterized by usual stereological parameters as well as by the two-point correlation function. The results show that the effect of the exclusion zone relative to the usual uniform randomly nucleationNucleation can be significant.

To understand the thermodynamic propertiesThermodynamic properties of the Si–B binary alloys, experiments were performed to measure the electromotive force (emf) as a function of temperature (823–923 K) using solid-state electrochemical cells that can be represented as $$ {{\left( - \right)\text{Pt,Ar}} \mathord{\left/ {\vphantom {{\left( - \right)\text{Pt,Ar}} {\left\{ {\text{Si}\left\| {\text{CaF}_{2} } \right\|\,\,{{\left\{ {\text{Si}{-}\text{B}\left( {\text{alloy}} \right)} \right\}} \mathord{\left/ {\vphantom {{\left\{ {\text{Si} {-} \text{B}\left( {\text{alloy}} \right)} \right\}} {\text{Ar},\text{Pt}}}} \right. \kern-0pt} {\text{Ar},\text{Pt}}}\left( + \right)} \right.}}} \right. \kern-0pt} {\left\{ {\text{Si}\left\| {\text{CaF}_{2} } \right\|\,\,{{\left\{ {\text{Si} {-} \text{B}\left( {\text{alloy}} \right)} \right\}} \mathord{\left/ {\vphantom {{\left\{ {\text{Si} {-} \text{B}\left( {\text{alloy}} \right)} \right\}} {\text{Ar},\text{Pt}}}} \right. \kern-0pt} {\text{Ar},\text{Pt}}}\left( + \right)} \right.}} $$ The activities of Si in Si–B alloys were calculated from the experimental emf data obtaining from the solid-state heterogeneous phase equilibrium. The activities of B in Si–B alloys were determined using the Gibbs-Duhem equation. The integral Gibbs energyEnergy of mixing $$ (\Delta {\text{G}}^{\text{M}} ) $$ of alloys were calculated from the partial Gibbs energies of mixing $$ \Delta \overline{\text{G}}^{\text{M}} $$ of Si and B and compared with the ideal Gibbs energyEnergy of mixing $$ (\Delta {\text{G}}^{{{\text{M}}, {\text{ideal}}}} ) $$ . A significant negative deviation was found for the integral Gibbs energyEnergy of mixing $$ (\Delta {\text{G}}^{\text{M}} ) $$ of alloys from the ideal Gibbs energyEnergy of mixing $$ (\Delta {\text{G}}^{{{\text{M}}, {\text{ideal}}}} ) $$ . The minimum integral molar Gibbs energyEnergy of mixing $$ (\Delta {\text{G}}^{\text{M}} = - 13.08 \,{\text{kJ}}/{\text{mol }}) $$ was found at xB = 0.8

Medical Mg-based alloys are extensively applied because of its degradability, low elastic modulus, etc. In this study, Mg–3Zn alloy was prepared by semi-solid powder injection mouldingSemi-solid powder injection moulding , a novel method combining metal injection moulding and thixomoulding in one step. Firstly, pure Mg powders with 3 wt% of pure Zn powders (the mean diameter is 50 μm) were mixed, and then the mixture were injected at 540, 560, 580, 600, and 620 °C, respectively with the loading force of 5 t. The effect of injection temperature on the microstructureMicrostructure , and its corresponding mechanical propertiesMechanical properties were investigated. The densification process and combination mechanismMechanism were analyzed as well. The results show that as the temperature increases, relative density, the compressive strengthStrength and microhardnessMicrohardness increase first and then decrease when the temperature reaches to 620 °C. The highest relative density, microhardnessMicrohardness and compressive strengthStrength is 97.4%, 125 HV, 315.4 MPa, respectively at the injection temperature of 600 °C. The microstructureMicrostructure is mainly composed of α-Mg and intermetallic phasesIntermetallic phases (MgZn2, Mg4Zn7 and Mg51Zn20), the grain morphology is equiaxed grains with size of about ~30 μm. When injected at low temperature, the main combination mechanismMechanism of powders is hot rollingRolling densification. When injected at high temperatureHigh temperature , flowing and filling of liquid is the main combination mechanismMechanism . Broken-up of particles and deformation including viscoplastic deformation contributes to the densification. More Mg was dissolved into Zn as the temperature increases, and the liquid fraction is mainly influenced by the dissolved Mg content.

Modulation-Assisted MachiningModulation-assisted machining (MAM) is an emerging method of metal particulate production where the tool feed rate in a metal cutting process is modulated to form chip particles directly from a solid workpiece. During the cutting process, a periodic disengagement occurs between the tool and the workpiece forming discrete corresponding particles of uniform shape and size. As a result of the large plastic strains that occur during metal cutting, the final particle morphology (size and shape) produced by MAM is determined by the deformation conditions. Average strains in MAM are in the range of ~2–4 depending on the modulation and cutting conditions. Numerical simulationNumerical simulation and finite elementFinite element analysis have shown that the strain imparted in MAM can vary significantly even during the formation of an individual chip. The variation of deformation is a result of the transient nature of cutting and commonly observed in periodic deformation processes. In the present paper, the particle shape, strain and hardnessHardness were studied using Al6061-T6 as a model material. Particles of short fiber-like morphology were produced. The cross-sectional shape of the fibers was dictated by the amount and distribution of strain during the cutting process. HardnessHardness measured by nano-indentation at different points on the fiber cross-section varied between 1.7–2 GPa consistent with the variations in strain reported in individual MAM particles. Consequently, the cross-sectional shape of fibers differs from the one simulated using only process kinematics and assuming steady-state conditions.

Molten metal atomization in close-coupled gas atomization dies can operate between two limiting conditions, jetting and filming, together with several complex mechanisms: liquid-gas drafting, downward/upward shearing, melt bouncing, etc. Liquid jet deformation depends on flow and geometric parameters, such as liquid Reynolds, liquid Weber, and gas Mach numbers, as well as gas jet apex angle and melt tube tip extension and aspect ratio, among others. Understanding their effect is of importance for the metal powder making industry. Numerical gas atomization studies can provide approximated flow information and consider a wide range of conditions, beyond experimental reach. Here, 3D high-resolution simulations employing a 5-equation compressible flow model coupled with the volume-of-fluid method are compared with experiments, for liquid Weber number in the range of 1–30 and liquid Reynolds number below 10,000. This validation explores the predicting capabilities of the numerical model.

The separation and recovery of ultra-fine granular particles is a source of significant interest in a number of fields. Following is a general analysis of an experimental method for separating micron-scale particles with respect to their density and hydrophobicity. By employing fluid mechanics, mass dispersion, and surfactantSurfactant application techniques, it is possible to separate mixed micron-scale particles consisting of charcoal and tungsten carbideTungsten Carbide . Through the application of standing waveStanding Wave fluid mechanics, a consistent separation of the materials becomes an inexpensive and easily scalable process that could theoretically be utilized to separate numerous suspended colloids provided the appropriate initial conditions. This examination focuses on particle bulk behavior and kinetic behavior in suspension such that a consistent output at a relatively high average recovery rate (greater than 70%) for tungsten carbideTungsten Carbide can be consistently attained.

In this study, akermaniteAkermanite powder (Ca2MgSi2O7) was synthesized using ball-milling with subsequent annealingAnnealing at high temperatures. The influence of mechanical activationMechanical activation as well as annealingAnnealing temperature was investigated on the progress of akermaniteAkermanite formation. Thermal gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopyElectron microscopy (SEM), and transmission electron microscopyElectron microscopy (TEM)TEM were utilized to evaluate the ball-milled and heat-treated powders. The formation mechanismMechanism of akermaniteAkermanite was scrutinized. It was found that akermaniteAkermanite could not be synthesized directly and the formation of some intermediate compounds such as enstatite is unavoidable. AkermaniteAkermanite was synthesized after 20 h mechanical activationMechanical activation with subsequent annealingAnnealing at 900 °C for 1 h. The nanostructured akermaniteAkermanite powder had a crystallite size of 34 nm based on the calculations performed by the Williamson–Hall approach.

The adoption of 3D printing into mainstream manufacturing is considered not only as a highly flexible processing technique, but also as a technique that can be applied to functional materials such as inks, paste, polymers, ceramics, powders and organic materials. Advanced processing techniques such as extrusion-based printing and ink-based printing technologies are at the forefront of 3D printing technology. In traditional manufacturing, the ability to select from a variety of preformed processable polymers is a challenge. 3D printing, however, predominantly targets the production of polymeric parts and models, and gas sensors are no exception. Advantages of conducting polymers such as good sensitivity, selectivity, synthetic richness, low-temperature operation, low cost of materials, and the inkjet deposition of polymer material allow integration of sensor arrays and supporting circuitry. As a result, the designed sensor is capable of multi-parameter sensing such as mobility, transconductance, threshold voltage, thermochromism, electrochromism, gasochromism, etc. This review focuses on a recent breakthrough in 3D printed sensors for detecting pressure, temperature, gas, electric fields and color when exposed to external stimuli. It also discusses sensors which are 3D printed and/or integrated within 3D printed structures, particularly, polymer-based gas sensors and gasochromic devices.

Three-dimensional printingThree-dimensional printing is a novel technique offering the ability to print transdermal drug delivery systemsTransdermal drug delivery systems on demand. Such printing techniques have already been used in the fields of dentistry, orthopedics and pharmaceuticalsPharmaceuticals ; highlighting the latter, printing medical devices and various active pharmaceutical ingredient formulations, which possess various geometries with controlled release characteristics, have also been utilized. An overview of these pharmaceuticalsPharmaceuticals is presented in this study, with an emphasis on transdermal patches that can be 3D printed. Several printing technologies and material systems are discussed, which are customizable and generate complex geometries with inherent precision that satisfy the transdermal system and enhance bioavailability. Case studies, advantages and limitations of the technology are discussed. Industry forecasts based on this technology is predicted to reach over USD 8 Billion by 2025, but the pharmaceutical industry is conservative and utilizes cost-effective methods for large-scale production. 3D Printing3D printing could revolutionize current ‘one size fits all’ manufacturing and would be utilized throughout the drug development timeline.

Formulating UV curable resinsUV curable resins for Additive ManufacturingAdditive manufacturing (AM), or 3D printing3D printing , is an area that spans various industrial sectors from adhesives, inks and optical fibers to nanotechnology and biomaterialsBiomaterials . UV curable resinsUV curable resins such as epoxides, vinyl ethers and acrylates are also important monomers that offer effective media for energetic materialsEnergetic materials . The potential exists to develop environmentally friendly formulations with suspended energetic materialsEnergetic materials at various solid loading levels. Developing techniques for UV curing formulations of highly loaded energetic suspensions is a challenging feat that must satisfy several requirements and produce a high-quality formulation with synergistic ingredient combinations to enhance propulsion phenomena. The candidate formulation must be able to operate in a sterolithographySterolithography (SLA) resin tank, meaning the suspension must be at least as fluidic as conventional SLA resins; and a thorough understanding of the polymerization cure kineticsKinetics , photoinitiation and cure depth is required. This is due to the fact that these are dominating factors for processing and formation of polymer network structure that exhibits good mechanical propertiesMechanical properties .

MARSMagnetic Augmented Rotation System (MARS) ––Magnetic Augmented Rotation SystemMagnetic Augmented Rotation System (MARS) has been proposed as a potential alternative in the field of renewable and sustainable power generation systems. MARSMagnetic Augmented Rotation System (MARS) is a device that realizes contactless torque transmission by utilizing a directed magnetic force. The aim of this paper is to study the configurations, results, applicationsApplications and 3D printing3D printing of gearsGears in relation to MARSMagnetic Augmented Rotation System (MARS) . In this work, we present several prototypes of the contactless mechanical torque-transmitting/power-generating systems. We summarize the main characteristics and range of applicationsApplications for most appropriate configurations of MARSMagnetic Augmented Rotation System (MARS) ; we show experimental results of the most recent developments by analyzing their performance.

Sustainability in production and avoidance of harmful substances are widespread drivers for further developments of production processes. In conventional deep drawingDeep Drawing , for example, mineral lubricants are usually used to reduce friction or wearWear and to avoid surface damage to components. These lubricants often contain harmful additives such as chlorinated paraffins. Furthermore, the lubricants must be applied to the sheet metal before the forming process and removed again, as they have a negative influence on subsequent processes such as bonding, welding and painting. In order to counter these disadvantages a new tribological system for deep drawingDeep Drawing processes was developed using volatile media (nitrogen or carbon dioxide) as lubricant. The advantages are avoidance of harmful substances and reduction of necessary process steps, since these media are introduced directly into the tools during forming and evaporate without residue after the process. In this context, the present work deals with experimental investigations on the tribological friction conditions at tool radii using volatile lubricants, such as CO2. In order to keep the multitude of possible influences on the tribological system as low as possible, the investigations were carried out on a strip drawing testing rig with simple deflection. The aim of the investigations was the characterizationCharacterization of the tribological system and the friction conditions at tool radii under varying boundary conditionsBoundary conditions such as retention force and injection angle of the lubricant.

Processes in cold formingCold forming are accompanied by high process loads, which are reduced by means of lubricants. Lubricants are ecologically and economically questionable and increasingly restricted by legislation. In a current research project, the substitution of lubricants by coatings for tools and texturing of workpieces in a full forward extrusion process is investigated. Exact friction values of combinations of texturing and coatingCoating are necessary to investigate the process numerically and experimentally. For solid forming, the ring compression test has proven to be a valid analogy test for determining the friction factor. In this paper, the latest investigations concerning the dry tribological contact of coated and uncoated tools with different textured workpiece surfaces are shown in the ring compression test. The flow and adhesion behavior of the active partners under loads of cold formingCold forming are investigated. Furthermore, the friction factor for numerical investigations of full forward extrusion process is determined.

Emissivity is defined as the ratio of the energyEnergy radiated from a material’s surface to that radiated from a blackbody (a perfect emitter) at the same temperature and wavelength and under the same viewing conditions. It is a dimensionless number between 0 (for a perfect reflector) and 1 (for a perfect emitter). Knowledge of surface emissivity is important both for accurate non-contact temperature measurement and for heat transferHeat transfer calculations [1]. Piobert’s Law states that all burning occurs at the surface layer by layer and the burning is normal to the surface [2]. This may cause changes in the burn surface response depending on the surface. Another important characteristic of combustion is Saint Robert’s Law (a.k.a. Vieille’s Law) which explains the effect of pressurePressure [3]. This paper will investigate through literature and propose a technical approach. The goal will be to assess the effect of a materials emissivity to its combustion behavior and identify a correlation if one exists. As stated above, emissivity does influence heat transferHeat transfer which is also a contributor to combustion behavior.

Conventional materials often fail in various ways even from relatively low-impact cyclic forces. In order to combat this phenomenon, smart materials have been developed. They exhibit adaptive capabilities to external stimuli, such as physical, mechanical or chemical changes in their environment. This makes them a topic of immense interest as they have many applicationsApplications of importance in the scientific field. In order to make advancements of significance in this arena, a better understanding of the fundamentals is required. This overview attempts to summarize the self-healingSelf-healing mechanisms in a wide variety of materials including natural composites, polymers, metals and ceramics.

An in situ X-ray radiographic study on the grain nucleationNucleation and grain growthGrain growth of inoculated Al–10Cu and Al–20Cu alloys during isothermal melt solidificationSolidification and directional solidificationSolidification conditions with constant cooling rates has been carried out. The influence of additional level of inoculation particles, cooling rates, and temperature gradient on the nucleationNucleation rate and growth kineticsKinetics of grains have been quantitatively studied. The deterministic nature of the heterogeneous nucleationHeterogeneous nucleation of aluminiumAluminium grain on inoculant particles is revealed. Numerical microstructureMicrostructure models have been developed to simulate the nucleationNucleation and growth behavior of aluminumAluminum grains and a good agreement between the experimental results and simulationSimulation results have been achieved.

Twin-roll casting of magnesium alloys is seen as a promising processing route to enable further development of advanced magnesium sheets for mass production. The reduction in the number of processing steps to final gauge leads to shorter production times and a decrease in production costs. The new production process for magnesium sheets allows the development of a new generation of magnesium alloys. The microstructure evolution during solidification between the TRC rolls is of great importance and can be influenced by alloy composition, addition of grain refiner or by variation of the process parameter. In the twin-roll casting process, liquid metal is pumped from furnace or cast over a pipe into a tundish. The melt is then dragged into the roll gap of a pair of counter rotating, internally cooled rolls. The metal solidifies upon contact with the cooled rolls is rolled to a strip. Such strips are used as feedstock material for rolling sheets to final gauge. This presentation will discuss the effect of the influencing variables on the quality and performance of Mg sheets on the example of AZ31 sheets. The influence of the strip properties and the rolling process parameters like temperature and degree of deformation on the microstructure, the texture and the mechanical properties of the strip is presented and discussed.

The concept for the Light MetalsLight metals Alliance arose from discussions in 2001 among Prof. David StJohn (then Research Program Leader of CAST, Australia), Dr. Jennifer Jackman (then Director General of CANMET Materials Technology Laboratory) and Dr. Helmut Kaufmann (then Director of LKR, Austria). The objective of the Alliance is to enable better use of light metalsLight metals in a broad range of real-world applicationsApplications through collaboration and knowledge exchange. This is accomplished by exchanges of personnel for research and technology transfer. Members also organize a biennial conference (Light MetalsLight metals Technology—LMT) showcasing government/industry/academia collaborations. Since 2001, membership has grown from 3 to 11, and there have been numerous scientific exchanges yielding more than 50 co-authored publications and 8 LMT conferences. Research covers all aspects of the production of parts from light metal alloys and composites, and the assessment of their mechanical and corrosionCorrosion performance. The presentation will highlight success factors and achievements over the 17-year history of the Alliance.

The article presents the results of an experimental study of the effect of impurity transport in a zone-refiningZone-refining system. In order to further improve the purity of aluminumAluminum , therefore, a sample with the purity (99.99%) aluminumAluminum material was used for zone refining, and evaluated its purity by glow discharge mass spectrometry (GDMS). In addition, the distribution of impurities after approximately 5 passes of zone refiningZone refining was analyzed. In experiments, when the zone speedZone speed was increased from 5 to 30 mm/min at a zone width of 40 mm, and the zone refining were controlled 5 to 20 passes. The experiment result showed that impurities content was significantly affected by the difference in the number of zone passes. In addition, with the decrease of the moving speed of the meltingMelting zone, the content of impurities in the product was also gradually decreased by GDMS analysis.