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## Über dieses Buch

The Magnesium Technology Symposium, the event on which this collection is based, is one of the largest yearly gatherings of magnesium specialists in the world. Papers represent all aspects of the field, ranging from primary production to applications to recycling. Moreover, papers explore everything from basic research findings to industrialization. Magnesium Technology 2021 is a definitive reference that covers a broad spectrum of current topics, including novel extraction techniques; primary production; alloys and their production; thermodynamics and kinetics; cast products and processing; wrought products and processing; forming, joining, and machining; corrosion and surface finishing; structural applications; degradation and biomedical applications; and several others.

## Inhaltsverzeichnis

### Influence of Layer Thickness on Deformation Twinning in Mg/Nb Laminates

Abstract
Mg-based nanolayered composites can achieve remarkably high specific-strengths due to a combination of a high density of bimetal interfaces and the light-weight constituent Mg phase. However, their applicability to load-bearing applications is hindered by limited formability and the anisotropic effects of deformation twinning. Understanding the microstructural and interface properties that control twinning is crucial for the design of multilayered composites. In this study, we employ an elasto-viscoplastic fast-Fourier-transform (EVP-FFT) crystal plasticity micromechanics model to examine the effect of Mg layer thickness on the growth propensity of $$\left\{ {10\bar{1}2} \right\}$$-tensile twins that span the entire Mg layer. The analysis shows that a critical Mg layer thickness exists, below which, twin growth becomes substantially harder. This critical thickness is related to the backstresses that develop along the twin boundary in the anti-twinning direction. These backstresses result from the plastic reaction of the adjacent Nb layers to the twin shear where the Mg twin lamella intersects the Mg/Nb interfaces. Below the critical layer thickness, the strong backstresses from both ends of the twin strongly interact. They increase in intensity as the layer thickness reduces. Concomitantly, increasing amounts of external loading are required to overcome the backstress and make twin growth feasible.
B. Leu, M. Arul Kumar, Irene J. Beyerlein

### Measurement of the Critical Resolved Shear Stress for Slip in Mg Alloys Using Instrumented Indentation

Abstract
A critical challenge for the plasticity and fracture of magnesium and its alloys is the competition between the different deformation modes and how this varies with temperature. In the current study, the critically resolved shear stress for basal slip as a function of alloy composition and temperature has been measured using instrumented spherical indentation. Indentation offers the advantage that tests can be conducted on grains of known orientation in polycrystal samples, particularly of importance for alloys where producing single crystals is difficult. Here, it will be demonstrated that by doing tests with indenters of different radii, the critically resolved shear stress (CRSS) for can be extracted. Very good agreement was found between the CRSS values for basal slip by indentation and the literature values from single crystal tests. Finally, the contribution will also offer perspectives on quantifying additional deformation modes such as extension twining and 2nd order pyramidal slip.
Warren Poole, Shuheng Li, Ghazal Nayyeri

### Development of a Low-Cost and Room-Temperature Formable Mg Alloy Sheet with In-Plane Isotropic Tensile Properties

Abstract
Twin-roll-cast Mg-3.07Al-0.25Mn (mass%) alloy was continuously rolled at a warm temperature, and the room-temperature stretch formability, tensile properties, microstructures, and texture of the annealed sheets were investigated. The sheet rolled at 220 °C exhibits large Index Erichsen values over 8 mm due to the formation of a ring-like texture feature where the basal poles are oriented ~25° from normal direction to all directions. Fine grain structure with an average grain size of ~7 µm could be obtained, so that the sheet shows moderate 0.2% proof stress of ~160 MPa and large elongation to failure over 25% in both rolling and transverse directions. The fabrication process of the alloy sheet, which consists of homogenization, warm-temperature rolling, and annealing, is viable in industrial production and accordingly, the alloy sheet developed in this work will broaden the commercial applications of wrought Mg alloys in automotive industries.
Taiki Nakata, Chao Xu, Hideaki Ohashi, Yu Yoshida, Katsuhito Yoshida, Shigeharu Kamado

### Microstructure and Fracture Toughness of an Extruded Mg-Dy-Nd-Zn-Zr Alloy Influenced by Heat Treatment

Abstract
The influence of microstructural changes induced by heat treatment on fracture toughness is investigated for a resorbable Mg-Dy based alloy. The initial hot-extruded condition is a fine-grained Resoloy® (Mg–Dy–Nd–Zn–Zr) alloy consisting of lamellar LPSO structures within the matrix. Solution heat treatment causes grain growth and the formation of blocky LPSO phases. The amount of the lamellar LPSO structures reduces. Quasi-static C-ring tests with and without Ringer solution were used to evaluate force–displacement curves and their fracture energy. The coarser-grained alloys tend to twin under plastic deformation, which is influencing the crack propagation. Blocky LPSO phases clearly hinder crack growth. The fine-grained extruded condition shows the highest force and displacement values to induce the crack, the solution heat-treated microstructure consisting of a good balance of grain size, matrix, and blocky LPSO phases and twins show highest fracture energy. Even if there might be an absorption of hydrogen, the ductility under stress corrosion is high.
Petra Maier, Benjamin Clausius, Charis Joy, Roman Menze, Benjamin Bittner, Norbert Hort

### The High-Solution Design of Magnesium Alloys

Abstract
The broad applications of Mg alloys are still limited by poor mechanical properties and poor corrosion resistance. Our group has found strength, ductility, as well as corrosion resistance of Mg alloys can be synergic enhanced by solution elements in primary Mg phase. However, most elements only show limited solubility in α(Mg) phase. We proposed that by dissolving multi-elements in the α phase, the enhanced entropy may bring enlarged solution and cocktail effects to the final properties of Mg alloys. This solubility extension possibility was firstly investigated in this work using thermodynamic evaluation based on connected databases. Thermodynamics indicates that the solubility of Rare-earth elements (REs) in α phase can be extended by the synergetic dissolving of Li and REs in α phase. This finding is instructive for the design of high solution of Mg alloys, and provides a new strategy for improving the performance of Mg alloys by high-solution design (HSD) of primary phase in alloy.
Jun Wang, Yuan Yuan, Xiongying Cheng, Tao Chen, Bin Jiang, Dajian Li, Aitao Tang, Torben Boll, Fusheng Pan

### Accounting for the Effects of Dislocation Climb Mediated Flow in Mg Alloy ZK10 Sheet

Abstract
Tensile samples of an Mg alloy ZK10 sheet were tested at a range of temperatures and strain rates designed to rather evenly probe a range of Zener Hollomon parameter values, from ln(Z) ≈ 15 (10–4 s−1 and 623 K) up to ln(Z) ≈ 50 (10–3 s−1 and 300 K). In contrast with more commonly examined Mg alloy AZ31B sheet material, ZK10 sheet material shows modest strain anisotropy (r-value) at low temperatures for both 45° (r45 ≈ 1.2) and TD (rTD ≈ 1.4) sample orientations, despite showing evidence of significant prismatic slip of <a> dislocations, which often leads to high r-values at low temperatures. These low r-values become even lower (r45 ≈ 0.84 and rTD ≈ 0.89) at high temperatures. These behaviors are hypothesized to occur due to a distinct initial texture and deformation mechanism activity, which includes a modest level of tensile twinning and <c + a> slip at both room and elevated temperature. A version of the viscoplastic self-consistent (VPSC) code, which accounts for the kinematics of dislocation climb, is used to simulate the behavior of a textured Mg alloy ZK10 sheet reveals that both the glide of pyramidal <c + a> dislocations and the climb of basal < a > dislocations are required to describe the behavior at elevated temperatures.
Michael A. Ritzo, Sean R. Agnew

### Interactions of a Basal Edge Dislocation with Vacancies and Interstitials in Magnesium

Abstract
As the lightest structural metal, magnesium (Mg) and its alloys have an important application on aircrafts, and would work under an irradiation condition, i.e. in outer space. So it is significant to study the microstructure and mechanical property of irradiated magnesium. In this work, we performed molecular dynamics simulations on the interactions of basal edge <a> dislocations with interstitials and vacancies. We found that both point defects have a blocking effect on dislocation motion. However, the blocking effect of interstitials is much stronger than that of vacancies. This is due to the different interaction types. The interstitials are absorbed by the basal dislocation, so the stronger blocking effect is a result of the short-range interaction, while the weaker blocking effect of vacancies is induced by the long-range interaction only since vacancies cannot be absorbed. Current work is useful for understanding the irradiation effects in magnesium and its alloys.
Defei Li, Jing Tang, Zikun Li, Xiaobao Tian, Yan Li, Haidong Fan

### Three-Dimensional Interaction of Twin with Tilt Boundaries in Mg: Twin and Dislocation Transmission

Abstract
While both dislocations and deformation twins accommodate plastic shear, the former are linear and the latter are three-dimensional domains bounded by complex interfaces. Therefore, the transmission of twins is much more complex than that of dislocations. In this work, we characterize the reactions and possible scenarios of associated interactions between twins and tilt boundaries using both atomistic and phase-field simulations. We find that the interaction is a competition between slip and twin transmission, depending on the geometrical alignment of the slip and/or twinning systems, resolved shear stress, and short-range interactions between intrinsic defects within the twins and grain boundaries. More importantly, we find that lateral twin transmission is easier than the forward twin transmission. We use a phase-field model to systematically investigate the role played by interfacial properties of the twin, such as facet energies and mobilities, on lateral and forward transmission into neighboring grains.
Khanh Dang, John Graham, Carlos N. Tomé, Laurent Capolungo

### Thermally Activated Nature of Basal and Prismatic Slip in Mg and Its Alloys

Abstract
Throughout the literature, a large discrepancy exists among the activation volumes reported for Mg and its alloys. The present work surveys the reported values for basal and prismatic <a> slip of pure and alloyed Mg single crystals as well as polycrystals. A focus is placed on recent results obtained for rare earth element solutes, Sc and Y. The measured values are discussed in light of a recently developed predictive model for thermally activated basal-solute interaction in Mg alloys. It is found that if the single crystal activation volumes for basal slip in solid solution alloys are computed using the total stress instead of a presumed “thermal component” of the stress, i.e. admitting that thermal fluctuations can aid in overcoming any obstacles present in those materials, then the experimental results are in much better accordance with the theoretical predictions. Possible implications of the combined activities of different deformation modes on the activation volume of pure and alloyed Mg polycrystals are briefly introduced. Finally, using polycrystal elasto-viscoplasticity modelling, it is shown that under conditions relevant to tests performed on polycrystalline, solute-containing binary Mg alloys, basal slip can be the dominant deformation mode at 0.2% offset strain at which the initial activation volume is often assessed.
Mohammed A. Shabana, Jishnu J. Bhattacharyya, Marek Niewczas, Sean R. Agnew

### Mechanisms and Machine Learning for Magnesium Alloys Design

Abstract
We will show our extensive high-throughput studies for magnesium alloys through both the dislocation and twinning mechanisms. Possible descriptors for the mechanisms are explored and a united picture is demonstrated, which is consistent with available experiments. There are two major contributions of this work, i.e., (i) The relationship between two well-acknowledged deformation mechanisms based on dislocations is clarified; (ii) Machine-learning models show that it is possible to design ductile magnesium alloys without the prior knowledge of deformation mechanisms.
Zongrui Pei

### Three-Dimensional Atomistic Simulations of Non-cozone Twin–Twin Interaction in Mg—Role of Twin Stability and Mobility

Abstract
Given the ease of activation of tensile twinning on the $$\left\{ {10\bar{1}2} \right\}$$ planes in Mg, multiple $$\left\{ {10\bar{1}2} \right\}$$ twin variants can be activated and interact with each other. The outcomes of these interactions are twin–twin junctions (TTJs) that can serve as initiation sites for microcracks. Here, we investigate the 3D structural characteristic and evolution of the non-cozone $$\left\{ {10\bar{1}2} \right\}$$ twin–twin junctions using atomistic simulations. This comprehensive approach allows us to identify additional twin–twin boundaries (TTBs) such as the TTBBP and TTBK2. They formed due to the interaction between the basal prismatic (BP) and conjugate twin (K2) interfaces with the coherent twin boundary (CTB). Moreover, the TTJs associated with the $$\left\{ {\bar{1}2\bar{1}2} \right\}$$ TTBs are found to promote the growth of the 3-D twin along the normal and forward direction of the twin during the interaction and hinder the detwinning process when loading is reversed.
Khanh Dang, Carlos N. Tomé, Laurent Capolungo

### Understanding Twinning-Detwinning Behavior of Unalloyed Mg During Low-Cycle Fatigue Using High Energy X-ray Diffraction

Abstract
It is well understood that twinning during deformation plays an important role in deformation of Mg and its alloys [18]. In hexagonal close packed (HCP) Mg alloys, the dominant deformation mode at room temperature is <a> slip on the basal (0001) plane Mg [9, 10]. The other slip systems—prismatic <a> slip, pyramidal <a> slip, and pyramidal <c + a> slip—require much higher stresses to activate during deformation [11]. Mechanical twinning allows for grains to easily deform along their c-axis [12] and has been the focus of significant, active research [e.g., 1323].
Aeriel D. Murphy-Leonard, Darren C. Pagan, Armand Beaudoin, Matthew P. Miller, John E. Allison

### The Effects of Basal and Prismatic Precipitates on Deformation Twinning in AZ91 Magnesium Alloy

Abstract
The advancement of Mg-based applications is motivated by inherently the high specific-strength and low densities of Mg and its alloys. The AZ91 alloy is one such exemplary cast Mg alloy that is being considered due to its relatively high strength, excellent corrosion resistance and castability. However, like most Mg alloys, it is not yet widely used due to poor formability and a complex, anisotropic plastic response. These behaviors have been linked to their propensity to deform by twinning, in addition to slip. Furthermore, the grains in the AZ91 alloy contain β-phase precipitates, which are similar in size as the twin lamellae. In this study, we use an elasto-viscoplastic fast-Fourier-transform (EVP-FFT) crystal plasticity micromechanics model to examine the interactions between $$\left\{ {10\overline{1}2} \right\}$$-type extension twins and two types of precipitates—basal and prismatic precipitates. The calculations focus on conditions that determine whether the twin is blocked by the precipitate or can cross the precipitate by nucleating a new twin on the other side of it. The effects of twin thickness, relative to the size of the precipitate, and precipitate types are investigated. The analysis shows that both precipitates are effective at blocking the propagation of twins and limit their ability to thicken. The basal precipitates are, however, substantially easier to cross by the twin than prismatic precipitates. Furthermore, the thicker the twin is when it impinges on the precipitate, the higher the chance it can cross.
B. Leu, M. Arul Kumar, Irene J. Beyerlein

### On the Role of Crystallographic Anisotropy and Texture in Damage Tolerance of Magnesium and Its Alloys

Abstract
The remarkable crystallographic plastic anisotropy of magnesium and its alloys reflects in its polycrystal response via texture. While texture-strength linkages have been studied, the role of textural variability on damage remains elusive. The challenge is to obtain relevant metrics that relate the net plastic anisotropy to macroscopic modes of damage. A possible approach is to adopt mechanistic descriptions of the damage. Motivated by the recent experimental and theoretical works in this direction, here we appeal to the Hill yield function to characterize the net plastic anisotropy of polycrystalline magnesium via the Hill plastic anisotropy tensor $${\mathbb{h}}$$. Metrics based on the components of $${\mathbb{h}}$$ offer a way to predict damage as a possible damage predictor. Using the results from our recent extensive three-dimensional crystal plasticity simulations for a wide range of textures, we map the net plastic anisotropy on to the coefficients of $${\mathbb{h}}$$, separately for the tensile and compressive responses. Metrics based on these coefficients serve as indicators for the propensity of textured polycrystals to damage by: (i) porosity evolution, or (ii) shear instability. An attempt is made to understand the potential roles textural variability and crystallographic plastic anisotropy play in damage under different loading conditions.
Shahmeer Baweja, Padmeya P. Indurkar, Shailendra P. Joshi

### Eliminating Yield Asymmetry and Enhancing Ductility in Mg Alloys by Shear Assisted Processing and Extrusion

Abstract
Solid phase processing techniques such as friction stir welding, Shear assisted processing and extrusion (ShAPE)/friction extrusion and cold spray have been successfully demonstrated as promising thermomechanical methods to produce metallic materials with enhanced performance. In this study, AZ series with and without silicon, ZK60 Mg alloys in as-received forms (as-cast or as-extruded) were processed using Shear Assisted Processing and Extrusion (ShAPE). Microstructural characterization was performed using EBSD and TEM and revealed that as compared to the feedstock materials/billets, friction extruded Mg alloys had more uniform microstructure, equiaxed grains, finer and homogeneously distributed precipitates and chemical homogeneity. It was also observed that basal planes were not oriented parallel to extrusion axis. As a result, rod products exhibited significantly reduced (in some cases eliminated) yield asymmetry and achieved enhanced ductility, which were uncommon or difficult to attain using conventional processing techniques. In addition, modified texture likely suppressed deformation twinning under compressive deformation.
Dalong Zhang, Jens Darsell, Nicole Overman, Darrell R. Herling, Vineet V. Joshi

### Numerical Study of Multiaxial Loading Behavior of Mg Alloy AZ31 Extruded Bar

Abstract
During plastic forming of magnesium alloy parts, multiaxial deformation state with shear and normal strain components is frequently observed. Therefore, torsional, torsion-tension coupling, and torsion-compression coupling behaviors of AZ31 magnesium alloy extruded bars are numerically investigated. The elastic visco-plastic self-consistent model with the twinning and detwinning scheme, in conjunction with a torsion specific finite element method, is employed. Stress-strain response, twin volume fraction, relative activities of deformation mechanisms, and deformation textures are obtained and used to interpret the multiaxial deformation behaviors of Mg alloys.
Xiaodan Zhang, Qin Yu, Huamiao Wang, Peidong Wu

### Absorbable Wire Radiopacity: Influence of Composition and Size on X-ray Visibility

Abstract
Imaging systems employing X-rays (such a 2D projectional radiography, computed tomography, and fluoroscopy) are widely used in medicine to aid in surgical planning, intervention, and follow up. Visualization of medical devices using these techniques relies on differences in x-ray absorption between the medical device and the surrounding tissue. The amount of absorption of a given device is largely a function of its cross-sectional dimensions, density, and atomic properties. Consequently, imaging of relatively small devices, like stents, made of a low-density material, like magnesium, can be very challenging. The aim of this study is to quantify the relative radiopacities of key absorbable metal alloy systems, determine the influence of magnesium alloy composition on radiopacity, and estimate the diameters at which wires are no longer visible under typical clinical conditions. This is accomplished by producing wires from five different magnesium alloys, a zinc alloy, and an iron alloy, in sizes ranging from 0.2 to 1.0 mm diameter, and imaging on a clinical x-ray system.
Adam J. Griebel, Aubrey L. Ehle, Jeremy E. Schaffer

### Magnesium and Magnesium Alloy Powder Processing Towards the Development of Near Shape Structural Materials

Abstract
Near shape forming of magnesium (Mg) alloys offers a significant opportunity for structural material lightweight. In this work, conventional press and sinter near shape processing has been applied to commercial AZ91D and pure Mg powders. Results indicate these powders are reasonably compressible achieving green densities of 88 to 98% ρTh with limited cracking. Sintering of these compacted powders is challenging and requires both solid state and transient liquid phase mass transport apparently due to the inherent powder particle surface oxide layer. Resultant press and sintered materials are characterized for density, porosity distribution, hardness, microstructure, and phase development. Throughout this effort, specific attention is paid to the affect oxygen, as an adsorbed contaminant and a surface thin film, presents as an impediment to solid and transient liquid state densification. Results of this work are intended to advance near shape processing of Mg alloy and Mg powders for potential structural applications.
Steven C. Johnson, Dylan G. Goncalves

### Effect of Sintering Temperature on the Properties of AZ91 Foamed Magnesium Alloy

Abstract
Foamed magnesium alloy has similar porosity and mechanical properties to biological bone, and is often used as a substitute material for biological bone. AZ91 magnesium alloy has high corrosion resistance and is suitable as a substitute material for biological bone. In this paper, AZ91 magnesium alloy powder is used as the raw material and urea is used as the pore-forming agent. The powder is compressed into a cylindrical sample under a pressure of 11 MPa, and sintered at different temperatures. Conduct metallographic observation and mechanical performance test on the sample. The results show that the sintering temperature is between 520 and 550 °C is the most suitable, the compressive strength of the sample is up to 9.14 MPa, the porosity is large and the pore size is uniform, which meets the performance requirements of bone substitute materials.
Hanghang Zhou, Guibao Qiu, Zhenyun Tian, Qingjuan Li

### Effects of Hot Isostatic Pressing on the Microstructure and Properties of Mg-Gd-Y-Zn Alloys

Abstract
Hot isostatic pressing (HIP) treatment after solution treatment has been investigated on its effects on the mechanical and corrosion properties of Mg-Gd-Y-Zn alloys with high long-period stacking order (LPSO) 14H phase fractions. Plate and cylinder samples of three different compositions were cut from permanent mold castings. The alloy samples were solution treated for 25 h at 500 °C and processed with the following HIP conditions: 485–490 °C, 100–200 MPa, for 2 h. The mechanical properties generally increased with HIP. Under accelerated corrosion conditions (submersion in 3% KCl at a temperature of 90 °C), the corrosion rate was observed to increase after HIP. HIP was found not to change the density of the samples, indicating micro-porosity was not an issue. The change in corrosion rate and mechanical properties were a result of microstructural changes due to the HIP thermal cycle. CALPHAD (CALculation of PHAse Diagrams) modeling of the three compositions as well as scanning electron microscopy (SEM) microstructural observations of the alloys are provided.
Janet M. Meier, Josh Caris, Alan A. Luo

### Low-Cost Magnesium Primary Production Using Gravity-Driven Multiple Effect Thermal System (G-METS) Distillation

Abstract
Vapor compression distillation (VCD) in a gravity-driven multiple-effect thermal system (G-METS) distiller can reduce the energy use and cost of magnesium distillation refining by up to 90% versus today’s batch distillation processes. This could potentially provide a key unit operation for efficient primary production of magnesium from MgO, by molten salt electrolysis using a reactive cathode, e.g., liquid tin followed by VCD separation. This work presents a techno-economic model of cost, energy consumption, and emissions associated with magnesium primary production by this reactive cathode molten salt electrolysis process with a G-METS distiller. The model includes a mass balance with 17 elements, electrolysis process energy balance with carbon or solid oxide membrane anodes, and detailed operating and capital cost estimates. Based on the properties of magnesium and expected operating conditions, the cost of magnesium production using this process could be comparable to or lower than that of aluminum production.

### Efficient Low-Cost Gravity-Driven Multiple Effect Thermal System (G-METS) Distillation of Magnesium

Abstract
Vapor compression distillation (VCD) can reduce the energy use and cost of magnesium distillation refining by up to 90% versus today’s batch distillation processes. This work describes a new continuous gravity-driven multiple effect thermal system (G-METS) process for magnesium VCD with just one internal moving part. The distiller will likely use less than 1 kWh/kg magnesium product, and high throughput of the continuous process can lower capital cost considerably. A detailed thermal model of the system presented here describes multicomponent evaporation, and batch distiller experiments validate key components of the model. There are multiple alloy distillation challenges with potential solutions described here, including liquid diffusion resistance, aerosol carry-over, and removal of volatile elements such as zinc. This efficient low-cost process could play a key role in multiple new flow sheets, from magnesium alloy recycling to rare earth magnet recycling to primary magnesium production.

### Industrial Practice of Extracting Magnesium from Serpentine

Abstract
There are 140 million tons of nickel-containing serpentine mines in Tuquan County, Inner Mongolia, China. There is no industrial practice in the world to extract magnesium metal from magnesium silicate minerals. Laboratory research shows that it is difficult to extract magnesium metal from serpentine. Based on our laboratory research, an industrial demonstration production line with an annual processing capacity of 21,000 tons of ore has been constructed. Especially the continuous vacuum metal magnesium reduction furnace developed by ourselves is stable and reliable, which proves its feasibility. From ore crushing, grinding, ball pressing, reduction, to metal magnesium refining and casting ingots, the entire production line is fully continuous and automated. The production process has no carbon dioxide emission, clean production, high production efficiency, and low cost, which lays the foundation for large-scale industrialization of extracting magnesium metal from serpentine.
Huimin Lu, Neale R. Neelameggham

### Research on Extracting Magnesium from Carbide Slag and Magnesite in Flowing Argon Atmosphere

Abstract
Carbide slag is a kind of industrial waste produced from the calcium carbide industry, which is difficult to treat and cannot be used reasonably. In this paper, carbide slag as a calcium source for extracting magnesium was proposed, i.e., carbide slag was directly mixed with low-grade magnesite instead of dolomite as raw material for extracting magnesium without pretreatment. The process is simple to operate and can obtain metal magnesium while reducing nearly 50% of CO2 emissions in the process of extracting magnesium. In the work, the strength of pellets, the effects of Ca/Mg ratio, and calcination temperature on the recovery rate of Mg were investigated. The results showed that low temperature calcination was beneficial to reduction and the recovery rate of Mg increased with the increase of Ca/Mg ratio, and the reduction rate was 87.95% when the Ca/Mg ratio was 1.2.
Junhua Guo, Daxue Fu, Jibiao Han, Zonghui Ji, Zhi’he Dou, Ting’an Zhang

### Optimization of Mechanical Properties in Magnesium Zinc Alloys

Abstract
Magnesium-based alloys are being used today in various lightweight applications. The mechanical properties of magnesium-based alloys can be enhanced for such applications through a combination of annealing temperature and holding time of the magnesium-based alloy. The magnesium-based alloy under investigation in this study is Mg-5%Zn. The results of this investigation show that optimizing annealing time and temperature can achieve homogenization and enhance the mechanical properties and formability of Mg-5%Zn as seen in hardness test results for the homogenized samples.
Christopher Hale, Zhigang Xu, HongLin Zhang, Sergey Yarmolenko, Jagannathan Sankar

### Quantitative Analysis of Impurity Elements in Pure Magnesium by Glow Discharge Mass Spectrometry (GDMS)

Abstract
In this paper, the method of quantitative analysis by GDMS of Fe, Si, Cu, and other nine impure elements in pure magnesium was studied. The applicable method for the preparation of samples was confirmed. The isotopes, resolution, and the analysis conditions were optimized. In addition, RSF of these impure elements was obtained using standard samples in order to correct the standard RSF. The results showed that using wire cutting introduces fewer impurities. When the discharge current was 55 mA and the gas flow was 350 mL/min, matrix signal was stable and suitable. Quantitative analysis of samples with the RSF314 showed better precision and accuracy than using the standard RSF. Comparison with the results of ICP-AES, AAS, and ICP-MS, the testing results were closer to the standard value which were obtained by our studies. But our method was more convenient on sample preparation, faster analysis speed, and higher overall accuracy than other means.
Jinyang Zhao, Jian Wu, Baoqiang Xu, QiMei Yang, Bin Yang

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