Magnesium Technology 2023

Ten years ago, the American Invents Act was passed by Congress. Despite lofty intentions, the AIA significantly degrades the value of IP and patents. Terves has recently gone through an enforcement action against a large importer of foreign magnesiumMagnesium products. The current system is rigged against small company inventors, with non-technical administrative judges invalidating 84% of patents in favor of infringers, versus <50% by multiple skilled patent examiners during reexaminations. Enforceable IP is essential for American competitiveness to complete with subsidized, unregulated, and lower cost offshore locations. Terves is a member of the US InventorUS inventors, representing 60,000 inventors focused on restoring individual patent rights post AIA. Terves’ experience enforcing IP rights in today’s climate as well as US inventorsUS inventors pending bill to restore patent rights will be discussed along with potential strategies and actions that inventors can take to mitigate AIA limitations.

Thermal routes to produce primary magnesiumMagnesium metal are generally demarcated with lower capital costs. However, the range of operational costs are high depending on reduction reactor efficiencies and configuration, labor intensity, and the cost of reductant. Choosing a reductant material can be a challenge in terms of logistics, supply security, cost, and technical performance. Presented is an assessment of possible reductant materials and the interplay between heat of reaction, reactor and condenser design, byproducts, and the behavior and role of impurities. On one end of the reductant spectrum is the reaction of carbon and magnesia, generating exclusively a byproduct gas, along with the product magnesiumMagnesium metal, and virtually no solid residue. Conversely, the reaction between calcined dolomite and ferrosilicon generates virtually no byproduct gas and nearly 6×  more mass of calcium silicates than magnesium metal. These chemistries share engineering challenges that center on the method of recovery products.

Most metallic materials are often cast. This is a highly dynamic process where composition and solidification conditions can become a challenge due to the appearance of porosity, shrinkholes, segregations, and the formation of intermetallic phasesIntermetallic Phases. Heat treatmentsHeat treatment are applied to get rid of segregations, stable, and metastable intermetallic phasesIntermetallic Phases for homogenization purposes and to obtain a material that is homogeneous with an adjustable property profile. However, often it is observed that the dissolution especially of metastable phasesStable/metastable phase really takes long times (hundreds or even thousands of hours) and high temperature which is accepted in the academic world but not acceptable for real industrial applications due to time and costs. Especially for biodegradable metals, metastable phases perhaps could be regarded as “stable” when the time of absorption is in range of a few weeks only and could be used to adjust properties.

Bioabsorbable magnesium alloysMagnesium alloy have often been studied in the context of absorbing too quickly, with the goal of obtaining a slower absorption rate for adequate use as a temporary implant material. While this is an important challenge to overcome, it oversimplifies the needs of surgeons and patients while not accounting for the requirements of various applications and the technological complexities of absorption. Through our presented work, we are building magnesium alloyMagnesium alloy capabilities to engineer the bioabsorption profile for optimizing implant performance based on requirements such as implant size, time to healing, and anatomical differences.

It has been established that additions of Ca and Zn to magnesiumMagnesium can yield wrought materials with a weak crystallographic texture that is desirable for formability. This study explores how Zn and Ca additions affect the static recrystallizationRecrystallization kinetics and mechanisms in magnesium alloysMagnesium alloy compressed using a Gleeble thermomechanical processingThermomechanical processing simulator. The effect of these alloying additions on the texture evolution and grain growth kinetics during post-deformation annealing will be discussed.

MagnesiumMagnesium (Mg) and its alloys are the lightest structural metals with high specific strength. Yet they suffer from low ductility, which limits their wide industrial applications. The stacking fault energyStacking fault energy (SFE), which governs core structures and movability of dislocations, is an important property for understanding plastic behavior of Mg alloysMagnesium alloy. Although the SFEs of Mg alloysMagnesium alloy have been widely studied, general quantitative models to accurately predict SFEsStacking fault energy in Mg alloysMagnesium alloy are still absent. Moreover, the SFE of common ternary alloys is rarely studied. We carry out high-throughput calculations to show the effects of single solutes and solute pairs on SFEs in ternary Mg systems. With the help of machine learning, a theoretical model for predicting SFEStacking fault energy has been developed. The work provides some fundamental mechanistic insights for understanding dislocation behavior in Mg alloysMagnesium alloy, and useful ICMEICME tools in developing rational alloy design recipes towards Mg alloysMagnesium alloy with enhanced ductility.

Using molecular dynamicsMolecular dynamics (MD) simulations, microstructure evolution during nucleation and growth of the $$\left\{ {10\overline{1}1} \right\}$$ 10 1 ¯ 1 twin{101 ̅1} Twin in polycrystal Mg is studied. The results show that profuse basal stacking faults (BSFs) form inside the $$\left\{ {10\overline{1}1} \right\}$$ 10 1 ¯ 1 twin embryo and disconnectionsDisconnections with different step size are also characterized along the twinning boundary (TB) interface. The disconnectionsDisconnections can be divided into two types according to their mobility, i.e., mobile steps with height of $$2h_{0}$$ 2 h 0 and $$4h_{0}$$ 4 h 0 and immobile steps with $$h_{0}$$ h 0 and $$3h_{0}$$ 3 h 0 . We find that the front line of mobile steps is divided into small segments due to the BSFs, and each segment will move as a unit at different velocity. When the mobile interfacial steps are consumed at grain boundaries, new steps are nucleated and glide on the TB interface. Such a process leads to twinning growth in the lateral and vertical directions. These insights contribute to the fundamental understanding of twinning mechanism in Mg.

Low-alloyed Mg–Ca–Zn alloys are promising as a base system of heat-treatable wrought alloys because of their rapid age-hardenability. The trace addition of Zn plays a critical role in accelerating the age-hardening response and following precipitationPrecipitation behavior of Mg–Ca binary alloys. This study reports the role of Zn on the rapid age-hardening and precipitationPrecipitation sequence in a Mg–0.3Ca–0.6Zn (at.%) alloy during isothermal agingAging at 200 °C using positron annihilation lifetime spectroscopy (PALS), scanning transmission electron microscopy (STEM), and atom probe tomographyAtom probe tomography (APT). PALS analysis indicates the absence of excess quenched-in vacancies in the as-quenched condition. Instead, the smaller trapping sites, i.e., open spaces, can facilitate the formation of Ca–Zn co-clusters even in the as-quenched condition. APT analysis reveals that the number density of Ca–Zn co-clusters in the Mg–0.3Ca–0.6Zn alloy increases in the early stage of agingAging, while that of Ca clusters tends to decrease in the Mg–0.3Ca alloy. These results indicate that the rapid age-hardening is attributed to the formation of a large number of Ca–Zn co-clusters. Microstructure analysis using aberration-corrected STEM provides further insights into the precipitationPrecipitation process of the Mg–0.3Ca–0.6Zn alloy. The atomic structures and stability of precipitates are identified by first-principles calculationsFirst-principles calculations. A precise precipitationPrecipitation sequence is established as: S.S.S.S → G.P. zones → η″ → η′ → η′ pairs and stacks/η1 → η.

High-strength, lightweight magnesiumMagnesium (Mg) alloys have substantial potential for reducing the weight of automobiles and other transportation systems and thus for improving fuel economy and reducing emissions. However, the strong crystallographic texture of rolled Mg sheet leads to poor formability and anisotropy. In specific non-rare earth Mg alloysNon-rare earth magnesium alloys, annealing can be used to desirably weaken the texture. Here, we present a multiscale in-situ study on the recovery and recrystallizationRecrystallization of an 80% hot-compressed Mg–3.2Zn–0.1Ca wt% (ZX30) alloy using high-resolution 3D X-ray diffractionX-ray diffraction microscopy (HR-3DXRD) and dark field X-ray microscopy (DFXM). We track more than 8000 non-recrystallized grains during annealing. Relative changes in crystallographic orientation and volume of each recrystallized and non-recrystallized grain are measured as a function of annealing time. Finally, local strain and orientation are measured in the interior of the specific grains with a spatial resolution of 77 nm.

Hexagonal close-packed (HCP) magnesiumMagnesium metals are widely used in different industries due to their low density and high specific strength. Their applicability is restricted due to poor formability and pronounced plastic anisotropy. Commonly, the formability is improved by altering the chemistry (adding rare-earth elements like Y) or modulating the microstructure (e.g., grain refinement). Grain refinement alone cannot yield the desired ductility, and the scarcity of rare-earth elements also limits the alloying addition. In this work, using the crystal plasticity framework, the combined effect of Y-content and grain sizeGrain Size on the mechanical responses of Mg alloyMg alloys is studied. The influence of alloying is represented by varying the activation stress and hardening responses of basal, prismatic, pyramidal slip, and tensile twin systems. This detailed study provides a map of strength and tension–compression asymmetry for a wide range of Y-content and grain sizesGrain Size. This work provides a pathway to optimize the microstructure and chemistry to achieve excellent structural properties.

Deformation twinningDeformation Twinning is a mechanism of critical interest in magnesium alloysMagnesium alloy and other HCP metals, both due to its ability to accommodate strain and its tendency to contribute to failure by providing a preferential crack pathway along twin boundaries. This deleterious behavior is worsened by instances of twin transmissionTwin Transmission, where a twin impinging on a grain boundary nucleates an adjacent, connected twin in the neighboring grain due to intense local stresses. Many commercial Mg alloysMagnesium alloy feature coarse grain boundary intermetallic particles in their as-produced state which potentially impede or exacerbate the localized stresses that play a role in both twin transmissionTwin Transmission and twinning behavior. Combined EDS-EBSD is used to analyze grain boundary particles, deformation twins, and transmission events to determine how particle morphology, position, and grain orientation modify twinning behavior and transmission likelihood and how these findings compare to computational results from Crystal Plasticity—Fast Fourier Transform modeling.

The widespread implementation of Magnesium alloysMagnesium alloy for the automotive industry warrants an improvement in their corrosionCorrosion performance and their ability to withstand dissimilar material contact under corrosive environments. Solid-phase coating methods offer opportunities to precisely tune the coating microstructure, thickness, and coating-substrate interface. We report on the optimization and characterizationCharacterization of cold spray deposited AA6061 aluminum alloy coatings on Magnesium alloyMagnesium alloy corrosionCorrosion and automotive components. Coatings with low porosity, high thickness, hardness, and excellent corrosionCorrosion properties were achieved using a bond coating composed of pre-treated CP-Al powders. The dynamic nature of the cold spray process enabled the formation of a metallurgical bond at the coating-substrate interface leading to high adhesion strengths. Furthermore, the ability of cold spray coatingsCold spray coatings to repair manufacturing defects was explored, and the microstructural mechanism for the same was investigated.

Use of Mg alloyMagnesium alloy structural parts can enable lightweight automobiles for improved energy efficiency. High corrosionCorrosion susceptibility of Mg alloysMagnesium alloy, however, remains as a technical challenge against their application in vehicle-structures. This work investigates open-air plasma assisted Si–O–C coating as a corrosionCorrosion barrier for AZ91D Mg alloyMagnesium alloy. The open-air plasma coating does not involve wet chemical process and is amenable to the industries experienced in other plasma-based processes. As-deposited coatings on AZ91D substrates were characterized by advanced microscopic characterizationCharacterization techniques, including SEM, STEM, and EDS. CorrosionCorrosion evaluation was performed using electrochemical impedance spectroscopy, polarization, and H2 collection measurements in 3.5 wt.% NaCl solution. Post-immersion AZ91D samples, that were uncoated or Si–O–C coated condition, were also characterized by SEM, STEM, and EDS. The results indicate that plasma assisted Si–O–C coating delayed the initiation of corrosionCorrosion and the progression of corrosionCorrosion attack.

Magnesium alloysMagnesium alloy have drawn considerable attention for several engineering applications, owing to their excellent properties like low density and high specific strength. The room temperature ductility and mechanical propertiesMechanical properties of Mg are usually enhanced by alloying additions. Based on the thermomechanical processingThermomechanical processing, the presence of critical concentration of alloying element typically leads to the formation of stable binary intermetallic phasesIntermetallic Phases with Mg, thereby distinctly altering the microscopic electrochemical properties of the alloy. However, the secondary intermetallic phasesIntermetallic Phases in Mg alloysMagnesium alloy are typically of sub-micron size; thus, accurate electrochemical characterizationCharacterization is a challenging issue. Using first-principles calculationsFirst-principles calculations, the electrochemical behaviorElectrochemical behavior of various Mg intermetallicsMg intermetallics was comprehensively quantified. The electrochemical polarization behavior of the intermetallics was strongly dependent on surface-mediated properties and chemical bonding characteristics. Finally, the computational framework provides an accurate screening tool that can assist in alloy design and development of coatings.

The corrosionCorrosion behavior of light metal alloys is complex due to the simultaneous interaction of variables such as processing history, microstructure, corrosive environment, and temperature. Each of these factors contributes to corrosionCorrosion damage at multiple length scales. This talk will focus on the combination of multimodal corrosionCorrosion with multiscale imaging to probe the corrosionCorrosion behavior of light metal alloys. This unique approach involves the simultaneous application of electrochemical methods such as Scanning Electrochemical Cell MicroscopyScanning Electrochemical Cell Microscopy (SECCM), in situ/ex situ imaging, and hydrogen collectionHydrogen collection. It is particularly beneficial to the study of complex heterogeneous microstructures (varying grain sizeGrain Size, chemical composition, porosity, nature of oxide film) obtained during processes such as Friction Stir ProcessingFriction stir processing and surface plasma treatment. Employing this approach correlatively over multiple length scales has aided in the identification of microstructural features that contribute to local and global corrosionCorrosion damage.

Magnesium alloysMagnesium alloy, with a high weight-to-strength ratio, have attracted considerable attention for lightweight applications, especially in automotive industry. However, their inferior corrosionCorrosion properties when in contact with aqueous solutions, salt, and other metals have become a significant hindrance to more widespread use of magnesium alloysMagnesium alloy. Surface coatingSurface coating has been considered an economic and effective strategy for corrosion protectionCorrosion protection of magnesium alloysMagnesium alloy. In this work, the corrosionCorrosion behavior of uncoated and micro-arc oxidationMicro-arc oxidation (MAO) coated cast, extruded, and forged AZ80 magnesium alloysMagnesium alloy has been studied using salt fog corrosionCorrosion chamber test and microscopic characterizationCharacterization techniques. The influence of the forgingForging process and MAOMicro-arc oxidation surface treatment on the corrosionCorrosion properties of the AZ80 magnesium alloysMagnesium alloy was investigated. The experimental results showed that the low forgingForging temperature of 250 °C led to fine grain sizeGrain Size and uniform distribution of secondary phase in the magnesium alloyMagnesium alloy, resulting in higher corrosionCorrosion resistance. The MAO coating provided significant corrosion protectionCorrosion protection of the AZ80 magnesium alloyMagnesium alloy substrates in the aggressive continuous salt fog environment.

The influence of the deformation speed in C-ring testsC-ring tests in Ringer's solution on crack initiation and propagation of extruded Mg10Dy and Mg10Dy1Nd is investigated. Deformation speeds varying from 2 to 0.012 mm/min allow corrosionCorrosion times from a few minutes to hours. Both the crack initiation force (higher for Mg10Dy1Nd) and displacement (higher for Mg10Dy) increase with decreasing deformation speed up to a corrosionCorrosion time of 1 h and then decrease, more for Mg10Dy1Nd and slightly more for the displacement compared to the force at higher corrosionCorrosion times. The decrease is associated with the higher corrosionCorrosion times—corrosion pits become visible at a test time of 1 h on the tensile side. In Mg10Dy1Nd the fracture toughnessFracture Toughness increases with decreasing deformation speed, and no clear picture is seen for Mg10Dy. Sub-cracks often initiate at corrosionCorrosion pits, which show a correlation to twinned grains at the tensile side—increasing fracture toughnessFracture Toughness.

Magnesium alloysMagnesium alloy are potential candidates for hard tissue replacements due to their structural and mechanical propertiesMechanical properties close to bone. Unlike conventional metallic implants, the corrosionCorrosion rate of magnesiumMagnesium is quite high. This will be an advantage if magnesium-based materials are used as biodegradable. In this study, Magnesium-based AZ31 and AZ91 magnesium alloysMagnesium alloy were coated with hydroxyapatite by plasma spray and electrostatic spray methods and their corrosionCorrosion rates were compared.

The addition of Y and Zn improves the property profile of Mg by forming a Long Period Stacking Ordered (LPSO) phase. The addition of Ag can further improve the degradationDegradation and mechanical properties. Owing to their biocompatibility and degradationDegradation under physiological conditions, these alloys are considered for temporary implants. Mg1.8Y0.6Zn and with the addition of 1 wt% of Ag were extruded and subjected to in situ tensile testing in air and submerged in simulated body fluid. At selected load intervals, synchrotron tomography was performed in order to follow the crack initiation and propagation in 3D. The results show the effect of corrosive media on the mechanical failure. Furthermore, the results are used to develop a computational model on stress corrosionCorrosion cracking that could be applied in failure prediction of implants and designing alloys for structural and medical applications.

Even with advances in minimally invasive surgery, open heart surgery remains a mainstay of modern medicine. In open heart surgery, the sternum is bisected to allow access to the heart. After surgery, the two halves of the sternum are mechanically fixed with stainless steel wiresWire or in some cases titanium or stainless steel cables and plates. These devices are left behind indefinitely and can in some cases cause patient discomfort or interfere with subsequent operations. An absorbableAbsorbable magnesiumMagnesium wireWire could allow for sufficient mechanical support while the sternum heals while avoiding the secondary complications of permanent materials. In this study, feasibility of a Mg sternal wireWire was assessed using a patent-pending LZ21 alloy wireWire and a simple sternal model mimic. Baseline mechanical and microstructural properties of 0.95 mm wireWire were established and compared to wireWire corroded in a modified Hank’s fluid while under tension.

This study focuses on the influence of inhomogeneous corrosionCorrosion on the quasi-static and cyclic properties of an Mg−Y−Nd alloy. Uniform corrosion is essential for biodegradable implantBiodegradable implants materials to avoid notching effects and premature failure. Previous studies on extruded Mg−3Y−3RE have shown a pittingPitting tendency in Ringer’s solution at 37 °C. Tensile testsTensile test on pre-corroded samples with different corrosionCorrosion extents, adjusted by corrosionCorrosion time, allow the correlation to residual tensile strengthResidual tensile strength. Corrosion fatigueCorrosion fatigue tests enable determination of the influence of the pittingPitting factor on service life and monitoring of the evolution of pits through electrochemical parameters. µCT scanning of corroded samples before and after the tests allows the identification of weak spots. Through3D-µCT analysis 3D-µCT analysis, it is possible to quantify the corrosionCorrosion extent and thus conclude that the amount and size of corrosionCorrosion pits are critical for shorter corrosionCorrosion times, whereas the residual load-bearing area is decisive for longer corrosionCorrosion times.

Barrel finishing is a well-established process in the industry for the targeted machiningMachining of surfaces. Especially small parts in large quantities with simple geometries can be easily machined this way. When investigating the biological behaviour of degradable magnesiumMagnesium implant alloys, platelets of 1 cm diameter and a thickness of slightly more than one mm are often used. Due to statistical requirements, a higher number of pieces are necessary. In addition, the geometry is comparatively simple. To ensure a certain reproducibility, all samples should also have comparatively similar surfaces. In this work, different abrasives and various process parameters are investigated to answer the question of whether barrel grinding is a viable process for producing reproducible specimens.

Magnesium alloysMagnesium alloy are used for structural applications in automobile and aerospace industries because of their lower density. Most magnesium-based components produced by casting or forming are of near net shape. Further machiningMachining is required to achieve dimensional accuracy and surface finish. So, magnesiumMagnesium machiningMachining is a topic of interest in many industries. In the present study, the machinability of magnesium RZ5 alloy (Mg-4.25 Zn-0.54 Zr-1.25 Ce) is evaluated with and without the use of cutting fluid. The cutting forceCutting force and surface roughnessSurface roughness are significantly affected by the feed rate and depth of cut; however, it is minutely affected by the cutting speed of the material. The use of cutting fluid with minimum quantity lubricationMinimum quantity lubrication reduces the cutting forceCutting force and increases the surface finish of the material. Due to the high-temperature gradient, smaller size chips were observed with lesser tool wear during machiningMachining of magnesiumMagnesium RZ5 alloy with minimum quantity lubricationMinimum quantity lubrication.

MagnesiumMagnesium predominantly exhibits a hexagonal lattice structure. The anisotropic distribution of activatable slip systems often leads to crystallographic preferential orientations during forming, whereby the anisotropic crystallographic properties show up macroscopically as anisotropic mechanical propertiesMechanical properties in components. Efforts to improve materials and optimize them should not only consist of mitigating or even preventing such anisotropic component properties. There is great potential to exploit them constructively. For this purpose, a 6 × 3 process matrix was designed using the magnesium alloyMagnesium alloy AZ31 as an example to investigate the influence of different forgingForging as well as forming routes on the properties of extruded round bars. Six different initial states of extrusionExtrusion billets and three different extrusionExtrusion dies were used, with one die designed for Equal Channel Angular Pressing in EXtrusionEqual Channel Angle Extrusion (ECAPEX) (ECAPEX). Forming behavior as well as microstructure and mechanical propertiesMechanical properties were investigated. Selected examples are used to present the results and evaluate the various influencing factors.

Long Period Stacking Order forming Mg-Rare EarthRare Earth-Zn alloys have attracted much interest due to high strength in the cast and wrought conditions. These alloys may find niche applications where high strength and thermal stability are desired for lightweight components. This presentation will detail the recent results of a production run Mg–Gd–Y–Zn–Zr alloy, cast and extruded at scale with 380 MPa tensile strength. AgingAging studies post extrusionExtrusion and post forgingForging resulted additional strengthening. Microstructure as well as extrusionExtrusion and forgingForging conditions will be linked to equilibrium phase diagramsPhase diagrams.

An open-source parallel 3-D crystal plasticity finite element (CPFE) software package, PRISMS-Plasticity, is presented here as part of an overarching PRISMS Center integrated framework. A new rate-dependent twinning-detwinning model is incorporated into the framework based on an integration point sensitive scheme to model Mg alloysMg alloys. The model includes both kinematic and isotropic hardening in order to handle cyclic response of structural metals. The model is validated versus high energy diffraction microscopy (HEDM) results of Mg alloysMg alloys during cyclic loadings. PRISMS-Plasticity TM is another feature which has been developed as a new open-source rapid texture evolution analysis pipeline based on the Taylor model, which is integrated into the open-source crystal plasticity software, PRISMS-Plasticity. The developed framework is used to capture the effects of alloying on texture development in Mg–Zn–Ca alloys. Finally, the PRISMS-Plasticity software has been integrated with the PRISMS-PF phase-field framework to model twinning within Mg alloysMg alloys.

While rare-earth Mg alloysMagnesium alloy have remarkable properties for high strength applications, lower cost alternatives are necessary for the widespread industry use of Mg. Ca added Mg alloysMagnesium alloy have shown promise as an alternative to rare-earth alloys. Ca-based precipitates can reduce basal texture, reduce casting porosity, and increase mechanical strength of cast components. However, the accumulation of Ca-based precipitates along inter-dendritic regions can severely limit ductility. Here, we apply two solid-phase processing techniques, friction stir processingFriction stir processing and shear assisted processing and extrusionShear assisted processing and extrusion, to produce wrought microstructure sheet and extruded tubes from a cast Mg–Al–Mn–Ca alloy. Ductility of the alloy is enhanced by densification under the applied thermomechanical processingThermomechanical processing conditions, grain refinement, and refinement of (Al, Mg)–Ca-based precipitates. Solid-phase processing provides a low cost opportunity to improve the properties of cast Mg alloysMagnesium alloy and improve service life.

The tensile properties and work hardeningWork hardening behaviour of die-cast magnesium alloyMagnesium alloy AE44 were investigated at a wide range of temperatures from 77 to 473 K and strain rates from 10–6 to 10–1 s−1. AE44 was also subjected to T5 ageing to understand the effect of heat treatmentHeat treatment on the work hardeningWork hardening behaviour. Both the as-cast and T5-aged AE44 showed a continuous decrease in strength and hardening rate with increasing temperature. A positive strain-rate sensitivity was observed over the entire temperature range. Voce hardening law was used to examine the work hardeningWork hardening behaviour, and it appears that the athermal hardeningAthermal hardening stage previously reported for magnesium alloysMagnesium alloy does not exist in AE44 for the studied temperatures and strain rates.

High-pressure die-cast magnesium (Mg) alloys are required for components working at temperatures above 200 °C. These new alloys are necessary for high-volume applications such as critical parts used for internal combustion (IC) engines in power tools. Here we present new developments of a Mg–RE die-cast alloy that shows excellent ambient and high-temperature tensile strength, creep resistanceCreep resistance, stiffness, and thermal conductivity, which are key advantages for alloys used at elevated temperatures. The excellent creep resistanceCreep resistance of the die-cast Mg3.5RE (La, Ce, Nd)1.5GdMnAl alloy, in comparison with its counterpart alloy without the Al addition, shows a significant improvement of the steady-state creep rate (SCR) at 300 °C/50 MPa. The synergistic effect of Al, Gd, and Mn has been found to induce a novel and thermally stable AlMnGd ternary short-range order (SRO, 0–2 nm)/cluster (2–10 nm) in the Mg matrix, which is believed to be responsible for the improvement in creep performance.

The condensation behaviorCondensation behavior of magnesium vaporMagnesium vapor in vacuumVacuum and argon was studied by inert gas condensation methodInert gas condensation method. The effects of heat source temperature 1273–1473 K on the macro morphology and condensation temperature of magnesium vaporMagnesium vapor condensation were obtained in vacuumVacuum and 0.2m3/h argon flowArgon flow. The results show that magnesium vaporMagnesium vapor condenses in a small area in vacuumVacuum, while the existence of argon would prevent the condensation process of magnesium vaporMagnesium vapor, resulting in the increase of the condensation area. The initial condensation temperature of magnesium vaporMagnesium vapor carried by argon is 974.0–1159.8 K, which is higher than 781.8–1034.8 K in vacuumVacuum; The condensed products with dense combination can be obtained in vacuumVacuum, while the condensed products with different particle sizes can be obtained in argon flowsArgon flow. A new idea is provided for the manufacture of magnesiumMagnesium powder and magnesium alloyMagnesium alloy through the condensation experiment of magnesium by inert gas condensation methodInert gas condensation method.

Recent global supply shortages, combined with need for light-weight structural components for efficient transportation, have led to very high prices for magnesiumMagnesium due to its low density and high part stiffness/weight. This study continues prior work on magnesium recycling using multiple-effect distillationDistillation with gravity as the parameter to create the pressure difference between effects, called G-METS. The long-term vision is for continuous distillationDistillation, but experiments to date have only used batch distillers with maximum rate of 1 kg/h. and minimum energy consumption of 2 kWh/kg. This study presents the design of laboratory-scale continuous distiller including a custom-made furnace to sustain a high-power density and temperature gradient for rapid boiling and efficient recovery of magnesiumMagnesium.

This paper introduces a new silicothermic processSilicothermic process, compound vertical retort technology for magnesiumMagnesium production. The workflow and key equipment and technologies were introduced. With the new technology, a demonstration unit was established in China. For the demonstration unit, the new equipment of lined steel retort was developed to solve the problem of “adhesion and glaze,” realizing the mechanical releasing slag; the new compound magnesium crystallizer with radiation heating surface and with function of sectional crystallization was developed to obtain magnesiumMagnesium metal of higher purity 99.8%; the new dual-regenerative furnace with combustion mode of double-deck, double-direction, hedging, suction, and reducing atmospheric firing was developed to realize temperature uniformity, and to further improve the combustion efficiency and heat efficiency. According to the actual production, these new technology’s economic and technical indices meet or even exceed the design expectations, significantly better than the Pidgeon process.

The use of biodegradable magnesiumMagnesium (Mg) alloys for bone fixationFixation devices has potential to improve patients’ quality of life by avoiding the necessary secondary operations conducted regularly for the removal of implants fabricated from conventional non-resorbable alloys. Mg-alloys have excellent biocompatibility and biodegradability along with a low modulus of elasticity which will decrease bone-shielding effects. However, low corrosionCorrosion resistance and relatively poor mechanical performance limit the use of Mg-based alloys for biomedical applications. This study focuses on the processing of Mg-Ca- and Mg-Sr-based alloys via powder metallurgical route. Thermodynamic calculationsThermodynamic calculations are used to predict the liquid phase fractions in order to optimise sinterabilitySinterability and porosity levels. Materials characterisation was conducted to validate the thermodynamic modeling results using optical and scanning electron microscopy (SEM/EDS) as wellX-ray diffraction as X-ray Diffraction (XRD).

The effect of agingAging heat treatmentHeat treatment on microstructure, hardness, and superelasticitySuperelasticity at room temperature was investigated herein for Mg-18.8 at.% Sc alloy. The hardness of the alloy is increased via agingAging heat treatmentHeat treatment at temperatures between 423 and 523 K, from ~ 90 Hv (as-quenched condition) to a maximum of 180 Hv. AgingAging heat treatmentHeat treatment at a higher temperature reduces the incubation time before the onset of age hardeningAge hardening. Scanning electron microscopy observations and X-ray diffractionX-ray diffraction analysis showed that the precipitationPrecipitation of hexagonal close-packed (α) phases within the body-centered cubic (β) matrix phase causes age hardeningAge hardening and the hardness value almost depends linearly on the volume fraction of α precipitates. Furthermore, the α precipitates formed via agingAging heat treatmentHeat treatment can be deformed along with β matrix phase upon stress-induced martensitic transformation in a sample with ~ 10% volume fraction of α precipitates, resulting in a slight reduction in stress hysteresis and a minor increase in superelastic recovery compared with the as-quenched condition.

Lightweight components improve the fuel efficiency of internal combustion vehicles and contribute to extending the driving range of electrified vehicles. Many Mg alloysMagnesium alloy have been developed over the years to meet these demands; however, low formability at room temperature, corrosionCorrosion, and high cost have inhibited widespread adoption in the automotive industry. The new alloy Mg-1Zn-1Al-0.5Ca-0.2Ce-0.4Mn (ZAXEM 11100, all in weight %) has shown excellent post-rolling formability with an Ericksen Index of 7.8 mm and a post-T6 yield stress of 270 MPa in lab scale sheet samples. In this work, a processing mapProcessing Map based on Gleeble thermomechanical tests has been developed for the new alloy. This processing mapProcessing Map provided important guidance to a production scale extrusionExtrusion. This work details the mechanical performance of ZAXEM11100 as an extrusionExtrusion alloy.

Mg-1.27Zn-0.75Gd-0.17Zr alloy (at.%) reinforced by long period stacking ordered (LPSO) structure X-Mg12GdZn was fabricated and then subjected to indirect extrusionExtrusion and T5 and T6 heat treatmentsHeat treatment, respectively. Effect of indirect extrusionExtrusion and heat treatmentsHeat treatment on microstructure evolution and room temperature tensile mechanical propertiesMechanical properties were systematically studied and discussed. Results show that the morphology of X-phase changes from plate-like to lamellar-like and further to disconnected block-like with the technical process. Large amounts of fine β´ phases precipitateΒ′ precipitate in α-Mg matrix of T5-treated alloy. Tensile and yield strength of the as-extruded alloy is 338 and 230 MPa, which is owing to the hard and fragile lamellar-like X-phase is easy to start cracks. T5-state alloy exhibits optimal mechanical propertiesMechanical properties with ultimate tensile strength of 390 MPa, tensile yield strength of 295 MPa and elongation of 11.9%, owing to the β´ precipitatesΒ′ precipitate strengthening and LPSO X-phase strengthening.

As a type of biodegradable material, AZ31 magnesium alloyMagnesium alloy has attracted much attention in the bio-implanting field. Depending on the actual applications, it is often necessary to modify the microstructure of materials to achieve different properties. It is critical to understand the relationship between microstructure and corrosionCorrosion property of AZ31 magnesium alloyMagnesium alloy. Grain sizeGrain Size is the microstructural feature studied in this work. Heat treatmentHeat treatment was employed to obtain the samples with different grain sizesGrain Size. Bio-corrosion test was conducted for the samples through being immersed in simulated body fluid for various time intervals. Scanning electron microscope was employed for observing morphology changes due to corrosionCorrosion testing. The results show that the corrosionCorrosion rates increased with the immersion duration for the samples, the samples with larger grain sizeGrain Size exhibited better corrosionCorrosion resistance, and the corrosionCorrosion mechanism was uniformly pittingPitting corrosionCorrosion.

In the present study, the microstructural evolution of solid-solution treated Mg–4Sn–3Al–1Zn–0.3Mn (TAZM) was explored through hot compression tests in the temperature range of 300–460 °C and the strain rate range of 0.001–1 s−1. Dynamic recrystallizationDynamic recrystallization (DRX) behaviors induced by hot compression and the effects of Sn alloying were studied, using analytical electron scanning microscopy. The correlation between DRX of α-Mg grains and dynamic precipitationDynamic precipitation of Mg2Sn during hot deformation was revealed. The influences of Mg2Sn dynamic precipitates over plastic deformation of α-Mg grains, texture evolution, and cracking were also discussed.

The aqueous Mg-ion batteriesAqueous Mg-ion battery (RMBs) have attracted lots of attention due to the high safety characteristics, low cost, and similar electrochemical characteristics to lithium. Magnesium orthovanadateMagnesium orthovanadate (Mg3V2O8, MVO) has stable three-dimensional framework and large ion channels and is expected to be a high-performance energy storageEnergy storage electrode material. Herein, low-cost Mg3V2O8 cathode for RMBs is prepared by high-temperature calcination with the aqueous MgAqueous Mg-ion battery2+ electrolyte. As a result, the MVO not only exhibits excellent electrochemical rate capability (the reversible discharge specific capacity is 143 mAh g−1 at the current density of 0.05 A g−1, and it still remains 61 mAh g−1 at a large current density of 4 A g−1), but also expresses good cycling performance (81% capacity retention after 10,000 cycles at the current density of 3 A g−1). This work proves that the MVO is an exceptional candidate for MIBs.