Magnesium Technology 2021: Poster Session
Sponsored by: TMS Light Metals Division, TMS: Magnesium Committee
Program Organizers: Victoria Miller, University of Florida; Petra Maier, University of Applied Sciences Stralsund; J. Brian Jordon, Baylor University; Neale Neelameggham, IND LLC
Monday 5:30 PM
March 15, 2021
Room: RM 31
Location: TMS2021 Virtual
Corrosion Behaviour of Shear Extruded Magnesium Alloy: Vikrant Beura1; Vineet Joshi2; Kiran Solanki1; 1Arizona State University; 2Pacific Northwest National Laboratory
Solid-state processing is an emerging technique to refine the microstructure promoting enhanced mechanical and corrosion properties in materials. To enhance the corrosion behaviour of magnesium alloy through these routes, in this work Mg-Al-Zn based magnesium alloy was processed through a novel solid-state process namely, shear assisted processing and extrusion (ShAPE). Post ShAPE processing, a microstructure with an equiaxed grain size distribution along with fragmented second phase particles was obtained. To understand the effect of obtained microstructure on the corrosion behaviour, potentiodynamic polarization and electrochemical impedance spectroscopy characterizations were performed. A noble pitting potential and reduced anodic dissolution kinetics in ShAPE processed sample were observed compared to as-received. To further support the electrochemical results post corrosion microstructural characterizations and x-ray photoelectron spectroscopy measurements were performed. Overall, a recrystallized microstructure with homogeneous grain size and second phase particle distribution have found to obtain better corrosion resistance in ShAPE processed magnesium alloy.
Corrosion Response of Friction Stir Processed EZ33 Mg Alloy: Vasanth Shunmugasamy1; Marwa AbdelGawad1; Eisha Khalid1; Bilal Mansoor; 1Texas A&M University at Qatar
Magnesium is one of the lightest structural metals with high specific mechanical properties and good biocompatibility making them an ideal candidate for biomedical implants. Mg has high corrosion rate in aqueous medium and presence of chloride ions leading to premature loss of mechanical properties. In the present work, a Mg-Zn-RE-Zr (EZ33) alloy is subjected to friction stir processing (FSP) and is evaluated for in vitro corrosion response. The Mg alloy subjected to FSP results in refined grains with fine distribution of the secondary precipitates. The refined grains help in obtaining higher mechanical properties and distribution of the precipitates help in the corrosion response. The processed alloy is studied for in vitro corrosion response in Hanks balanced salt solution maintained at 37±1°C to simulate human body conditions. Results from present study can help in microstructure engineering of Mg alloys with tailorable mechanical and corrosion properties for biomedical applications.
Effect of Annealing on Microstructure and Hardness of Mg-9Al Alloy Plates Processed by Single-pass Differential Speed Rolling: Honglin Zhang1; ZhiGang Xu1; Sergey Yarmolenko1; QiuMing Wei2; Laszlo Kecskes3; Jagannathan Sankar1; 1North Carolina A&T State University; 2University of North Carolina at Charlotte; 3Johns Hopkins University
In this study, a series of Mg-9Al plates were obtained from the initial 5 mm thickness by single-pass differential speed rolling (DSR), with a thickness reduction per pass of 10%, 20%, 40%, and 60%, corresponding to speed ratio of 2. The effect of different annealing temperatures and corresponding holding time on the microstructure, texture, and hardness were investigated. Key results showed that for the plates with deformation of 20%,40%, and 60%, which contained a lot of twins, the basal pole intensity decreased, and the hardness increased, resulted from the static recrystallization during the annealing processing. While, for the plate subjected to low deformation (10%), the basal pole intensity increased, due to the coarsening of the initial DRXed grains. In addition, some of the elongated grains remained un-recrystallized. This is attributed to the relative lack of formation of twins in these regions during rolling processing.
Eutectic Modification of Mg2Si in Mg-Si Alloys for Faster Hydrogen Absorption Kinetics.: Manjin Kim1; Julio Piraquive1; Yahia Ali1; Stuart McDonald1; Trevor Abbott2; Kazhuhiro Nogita1; 1University of Queensland; 2Magontec Ltd.
Trace elements such as Na, Sr, or other alkali and alkaline-earth elements have been widely studied as chemical refiners that change the morphology and the size of faceted eutectic Si in the Al-Si alloy system to improve mechanical properties. In this work, we have extended this technique to modify faceted eutectic Mg2Si in the Mg-Si alloy system for faster hydrogen absorption kinetics. Various amount of modifier elements were added into Mg-Si alloys and the microstructure of the Mg-Si alloys was investigated. A modification effect on eutectic Mg2Si was observed. The modification mechanism of eutectic Mg2Si in Mg-Si alloy and its potential effect on hydrogen storage properties are discussed.
Cancelled
In situ Study of Mg-Zn Alloy Degradation Mechanisms towards Advancing In Vitro Testing: Max Viklund1; Lars Wadsö1; Dmytro Orlov1; 1Lund University
Mechanisms of magnesium degradation in aqueous media still have many open questions because of complexity of the process and limitations of existing experimental methods. Development of the latter is critically important for advancing in vitro assessment of bio-degradable implant materials based on Mg alloys. Combining isothermal calorimetry with pressure measurements in a reaction cell during immersion testing allows in situ quantitative analysis of chemical reactions based on direct access to process thermodynamics, which is complementary to more traditional potentio- dynamic testing. We carried out in situ measurements of enthalpy, H2 generation and pH-factor evolution upon immersion of pure Mg and Mg-5%Zn alloy into 0.9%NaCl water solution and simulated body fluid. Mg degradation kinetics seems to be linear before and logarithmic after the saturation of pH. In Mg-5%Zn alloy, the kinetics return to linear after 15h, at which point degradation rate and enthalpy start increasing, which is associated with secondary reaction.
Liquid Enhanced Ga-Sn Alloy Anode for RMBs: Jiawei Liu1; Chao Song1; Yuan Yuan1; Dajian Li1; Fusheng Pan1; 1Chongqing University
The major problem of using pure Mg metal as anode of rechargeable magnesium batteries (RMBs) is the passive films formed in interface of anode and the polar organic electrolytes, which can block Mg ion in their migration towards the electrode surface. Therefore, Metallic anodes are proposed as the promising substitutes for a reversible electrode. . In this work, Ga-Sn binary alloys were prepared using a simple method. The high specific capacity, good cycling stability (more than 200 cycles) and great rate capability in conventional electrolyte were observed. The superior electrochemical performance of the Ga-Sn alloy-type anode is attributed to the reversible solid-liquid phase transformation at room temperature during cycling which can significantly improve the transport kinetics of Mg-ion. Meanwhile, the electrochemical mechanism was clarified by Ex-situ X-ray diffraction and transmission electron microscopy. The present investigation provides a new route to the development of metallic anode for magnesium-ion batteries.
Mechanical and Microstructural Behavior of Rolled AZ31B Magnesium Alloy under Three Different Stress States: Luiz Carneiro1; Duke Culbertson1; Qin Yu2; Yanyao Jiang1; 1University of Nevada, Reno; 2Lawrence Berkeley National Laboratory
The deformation behavior of rolled AZ31B magnesium alloy was experimentally investigated under three different loading modes: uniaxial tension, uniaxial compression, and free-end torsion. The tension and torsion specimens are cut along the normal direction of the rolled plate, while the compression specimens are cut along the rolling direction. The microstructure evolution of the material was examined by means of electron backscattered diffraction (EBSD), using companion specimens. The results show that compression evaluates the highest equivalent fracture stress and plastic strain hardening rate, following by tension, and torsion. Under compression, {10-12} twinning is dominated by single or double variants within a grain, while, under tension, multiple variants are activated, inducing substantial twin-twin interactions. Under torsion, {10-12} twinning is limited due to a significant fraction of the grains with negative resolved shear stress on the {10-12} planes. The role of twinning and slip mechanisms on the deformation of AZ31B are discussed.
Optimization of Mechanical Properties in Magnesium Zinc Alloys: Christopher Hale1; 1North Carolina A&T University
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.
Preparation of Thin-walled Magnesium AZ31 Alloy Tubes Using Friction Stir Extrusion: Vasanth Shunmugasamy1; Eisha Khalid1; Bilal Mansoor; 1Texas A&M University at Qatar
We have prepared thin walled (400 micron) AZ31 Mg alloy tubes using friction stir extrusion (FSE). The adopted methodology utilizes a rotating tool that is plunged into the workpiece. The friction between tool and workpiece results in elevated temperature and the plunged tool pushes the metal up, to form a tube. The process resulted in a defect free, well consolidated tube. The tube wall showed refined grains on inner edges near to the tool, resembling a stir zone. The refined grains and resulting texture developed on inner edges of the tubes had a profound effect on the microhardness and corrosion response. Corrosion response based on immersion in Hanks salt solution for 48 hrs showed corrosion attack starting from tube outer edges then moving inward. The results from present work show FSE process has great potential to develop Mg alloy tubes that can be precursors for biodegradable stents.
Role of Temperature and Pre-strain in Fatigue Strength of WE43-T5 Magnesium Alloy: Marko Knezevic1; Saeede Ghorbanpour1; Brandon McWilliams2; 1University of New Hampshire; 2CCDC Army Research Laboratory
This work investigates the effects of test temperature and sample pre-straining on the high cycle fatigue behavior of a magnesium alloy, WE43. Fatigue strength is found to deteriorate with environmental temperature from room to 100℃. The decline is associated with softening of the thermally activated deformation mechanisms in the material with temperature. In contrast to the samples pre-strained in tension, fatigue strength improves for the samples pre-strained in compression. The peak improvements of over 2x is determined for the samples pre-compressed to 6% strain. Significantly, the alloy sufficiently pre-strained in compression begins to exhibit the endurance limit. The interesting characteristics of the alloy behavior in fatigue upon pre-straining are rationalized and discussed in terms of the microstructural evolution as well as the underlying deformation mechanisms of slip and twinning causing hardening and forming localizations.