Magnesium Technology: Poster Session
Sponsored by: TMS Light Metals Division, TMS: Magnesium Committee
Program Organizers: Petra Maier, University of Applied Sciences Stralsund; Steven Barela, Terves, Inc; Victoria Miller, University of Florida; Neale Neelameggham, IND LLC
Monday 5:30 PM
February 28, 2022
Room: Exhibit Hall C
Location: Anaheim Convention Center
E-17: A Parametric Study of the Role of Basal-prismatic <a> Dislocation Interactions in Dynamic Strain Aging in Mg Alloys: Mohammed Shabana1; Jishnu Bhattacharyya1; Sean Agnew1; 1University of Virginia
The phenomenon encompassing negative strain rate sensitivity and serrated flow (i.e., dynamic strain aging) is observed in many alloys at a particular range of temperatures and strain rates. This also applies to Mg alloys where the interactions between mobile and forest dislocations are thought to be important in explaining this aspect. In 2004, Picu illustrated a mechanism for the appearance of the negative strain rate sensitivity and applied the mechanism to a parametric study of the Lomer lock case in FCC alloys. In HCP Mg however, locked configurations do not result from interactions between basal and prismatic <a> dislocations. Such interactions can either be collinear (leading to annihilation) or non-collinear (leading to glissile junction formation). These cases in which mobile basal dislocations interact with forest prismatic dislocations and vice versa are discussed in a parametric study along with their effects on dynamic strain aging in Mg alloys.
E-18: Corrosion Properties of Friction Stir Processed Cast Mg-alloys: Rajib Kalsar1; David Garcia1; Hrishikesh Das1; Venkateshkumar Prabhakaran1; Glenn Grant1; Darrell Herling1; Mageshwari Komarasamy1; Vineet Joshi1; 1Pacific Northwest National Laboratory
In this study, friction stir processing (FSP) has been utilized to modify the microstructure of high pressure die cast (HPDC) AZ91 Mg-alloy for improved corrosion properties. Processing parameters were optimized to obtain homogenous microstructure as well as defect-free processed region. A microscopic droplet-based measurement technique, called scanning electrochemical cell microscopy (SECCM) was utilized to measure the location-specific electrochemical properties. A theta probe with approximately 10 µm diameter was used to measure the electrochemical properties of Mg alloys from the base metal to the processed zone. Electrochemical analysis showed the processed zone is more cathodic compared to the base metal. Relatively higher cathodic nature of the processed zone indicates an improvement in the corrosion properties of the friction stir processed Mg alloys. Detailed microstructural characterization was carried out to correlate the microstructural features with the microscopic electrochemical response.
NOW ON-DEMAND ONLY – E-19: Effect of ECAP on Corrosion Properties of ZK40 Magnesium Alloy for Biodegradable Load-bearing Applications: Hamza Ghauri1; Marwa AbdelGawad1; Matthew Vaughan2; Bilal Mansoor1; Ibrahim Karaman1; Hans Maier3; 1Texas A&M University at Qatar; 2Texas A&M University; 3Leibniz Universität Hannover
Equal channel angular extrusion was employed on Mg-4%Zn-0.5%Zr (ZK40) to explore its potential for biodegradable orthopedic applications. The as-extruded and heat-treated starting material displayed inhomogeneous microstructure while after ECAP by 4Bc, significant grain refinement and precipitate modifications resulted in a relatively more homogenous microstructure. Preliminary investigations of time-dependent EIS plots and corroded surface morphologies revealed evidence of galvanic couples between populations of grains with different grain sizes as well as the grain matrix and the precipitates. The ultra fine-grained structure was also found to reduce the overall corrosion resistance of ZK40 indicating an underlying contributing factor which was linked to the composition and integrity of the developing surface film. Cross-section SEM images and X-ray photoelectron spectroscopy (XPS) results revealed a more compact and thicker surface film on pre-ECAP ZK40 despite having an inhomogeneous microstructure, in addition to evidence of the disassociation of Zr from the matrix into the surface film.
E-20: Effect of Minimum Quantity Lubrication on Machinability of Magnesium RZ5 Alloy: A Comparative study: Arabinda Meher1; Manas Mahapatra1; 1IIT Bhubaneswar
Magnesium alloys are used for structural applications of automobile and aerospace industries because of their lower density. Most of the magnesium-based components are produced by casting, and further machining is required. So, magnesium machining 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 force and surface roughness significantly affected by the feed rate and depth of cut and minutely effected by the cutting speed of the material. The use of cutting fluid with minimum quantity lubrication reduces the cutting force and increases the surface finish of the material. Due to the high-temperature gradient, smaller size chips were observed during machining with minimum quantity lubrication. The rate of tool wear is also reduced during machining of magnesium RZ5 alloy with minimum quantity lubrication.
E-21: Mechanical and Microstructural Behavior of Rolled AZ31B Magnesium Alloy Subjected to Multiaxial Stress State: Luiz Carneiro1; Qin Yu2; Yanyao Jiang3; 1University of Nevada Reno; 2Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley; 3University of Nevada Reno
The deformation of rolled AZ31B magnesium alloy was experimentally investigated under multiaxial loading. Specimens are prepared with their longitudinal axis oriented parallel to the normal direction of the rolled plate. Multiaxial tension-torsion and compression-torsion tests are conducted with different ratios of maximum axial strain to maximum shear strain. The results show that axial yield and flow stresses decrease with the introduction of simultaneous shear. The shape of the shear stress-shear strain curve is significantly affected by the multiaxial loading. The shear stress-shear strain curves display a strong sigmoidal shape under tension-torsion, while a concave-down shape is observed under compression-torsion. Post-fracture microstructural analysis shows that a significant fraction of the grains with negative resolved shear stress on the {10-12} planes display {10-12} tension twins under compression-torsion, indicating that Schmid criterion alone may not explain twin favorability. The fracture damage mechanisms are also discussed in terms of possible crack initiation sites.
NOW ON-DEMAND ONLY - E-22: Phase-field Modeling of the Effects of Second Phases on the Corrosion of Mg Alloys: Yanjun Lyu1; Vishwas Goel1; David Montiel1; Stephen Dewitt1; Alexander Chadwick1; Katsuyo Thornton1; 1University of Michigan
Magnesium alloys are known for having the highest strength-to-weight ratio among all structural alloys. However, one factor that limits their application is poor corrosion resistance, which is strongly dependent on alloy composition. For example, second phases in Mg alloys are often nobler than Mg matrix and act as cathodes, thereby promoting a microgalvanic effect which accelerates corrosion. Thus, understanding the effect of second phases on Mg alloy corrosion is crucial to designing corrosion-resistant alloys. In this work, we combine the phase-field model and smoothed boundary methods to investigate the microgalvanic effects of second phases on the corrosion behavior of Mg alloys. Starting from a microstructure representative of the alloy surface, we simulate the corrosion of the alloy when exposed to a well-stirred electrolyte. In particular, we investigate how the compositions of the alloy and second phases affect the overall corrosion rate and corrosion front morphology.
E-23: Possibility of Joining Explosively Welded AA1050/AZ31 Clad Plates Using FSW/Laser Hybrid Method: Marcin Wachowski1; Robert Kosturek1; Krzysztof Grzelak1; Janusz Torzewski1; Ireneusz Szachogłuchowicz1; 1Military University of Technology
AA1050/AZ31 bimetal clad plates were fabricated via explosive welding method. In this study the process feasibility, effect of processing parameters on microstructure and mechanical properties of the bimetal butt joints obtained by friction stir welding (FSW)/laser welding (LBW) hybrid method were investigated. Two procedures, one with a friction stir welding and the other with a single-side laser beam beam, were utilized for butt-joint welding. The evolution of microstructure from the base material to the stir zone was investigated using SEM/EDX and TEM techniques. Mechanical properties were investigated by microhardness and tensile tests with digital image correlation method. These investigations have shown the possibility of making good quality of the welds with low participation of defects using both experimental procedures.
E-24: Primary Production of Magnesium via Molten Salt Electrolysis with Reactive Cathode: Madison Rutherford1; Armaghan Telgerafchi1; Nicholas Masse1; Lucien Wallace1; Gabriel Espinosa1; Adam Powell1; 1Worcester Polytechnic Institute
Low-cost clean primary production of magnesium metal is important for its use in many applications, from light-weight structural components to energy technologies. Recently there has been renewed interest in MgO molten salt electrolysis with a reactive dense liquid metal cathode. This presentation will describe developments in this technology including techno-economic analysis, experiments with carbon and zirconia solid oxide membrane anodes, and new gravity-driven multiple effect thermal system (G-METS) distillation technology. It will also discuss cradle-to-gate life cycle analysis of magnesium metal production using this MgO reduction technology under several raw material and process technology scenarios, including effects of different raw materials, drying and calcining methods, molten salt compositions, electrolysis anode types, and distillation methods.
E-25: Process-structure-property-performance Relationship of Solid-state Additively Manufactured Magnesium Alloy WE43: Malcolm Williams1; Thomas Robinson1; Christopher Williamson1; Ryan Kinser1; Paul Allison1; James Jordon1; 1University of Alabama
In this research, Additive Friction Stir Deposition (AFS-D), a nascent solid-state additive manufacturing (AM) process, is utilized to deposit magnesium alloy WE43. To determine the viability of the AFS-D process, a parametric study was completed, determining an acceptable parameter with minimal surface defects and being fully dense. Using this parameter, a bulk WE43 deposit was created to conduct an in-depth study of the microstructure, mechanical response, and fatigue behavior as compared to the feedstock material. The bulk WE43 deposit exhibited a refined homogenous microstructure compared to the feedstock material. However, the as-deposited WE43 experienced a decrease in hardness and monotonic mechanical response when compared to the feedstock. At high stress amplitudes, the fatigue life experienced a decrease compared to the feedstock, however overlapping of data occurred at lower stress amplitudes. This study illustrates the potential of AFS-D magnesium alloy WE43 in AM structural components.
E-27: Towards High Hardness and Corrosion Resistant Mg Alloys Using High-energy Ball Milling: Mohammad Umar Farooq Khan1; Taban Larimian2; Tushar Borkar2; Rajeev Gupta3; 1Texas A&M University; 2Cleveland State University; 3North Carolina State University
There is considerable work aimed at improving the strength and corrosion resistance of Mg alloys. For the present work, the influence of alloying addition on the hardness and corrosion behavior of Mg alloys is investigated using high-energy ball milling (HEBM). Binary alloys were synthesized using HEBM and consolidated using cold compaction and spark plasma sintering. Phase analysis, hardness, and microscopic studies for alloys were done for comparison. Corrosion behavior was evaluated using potentiodynamic polarization tests in 0.1 M NaCl. Nanocrystalline Mg alloys with hardness greater than commercial alloys were obtained. All the binary alloys showed lower corrosion current densities when compared to milled Mg. Decreased cathodic kinetics with an increase in anodic kinetics was observed with Ge addition. The best set of properties was obtained for Mg-Al alloy. Understanding the effectiveness of added alloying elements will help with the development of future high-strength Mg alloys with lower corrosion rates.
E-28: Understanding Mechanisms of Electrocrystallization in Mg-based Batteries: Rachel Davidson1; Stefany Angarita-Gomez1; Perla Balbuena1; Sarbajit Banerjee1; 1Texas A&M University
Enabling the use of metallic anodes in rechargeable batteries offers an attractive path for providing substantial increases in capacity. Progress towards these efforts has proceeded cautiously however, as demonstrations of dendrite formation in lithium-based systems are abundant causing cell degradation and failure. While magnesium has often been cited as a prime candidate to enable use of metallic anodes due to its supposed imperviousness to dendrite formation, our recent demonstrations of the first definitive examples of dendrite formation in magnesium batteries revealed a diverse array of deposit morphologies ranging from fractals of aggregated hexagonal platelets to highly crystalline dendrites. Upon addition of alkylthiols, substrate-bound single crystalline magnesium nanowires are instead formed. Mechanisms of formation leading to this directed growth have been explored by combining detailed microscopy studies with molecular dynamic simulations. Understanding of the dynamics of deposition in magnesium systems opens the door for development of designs which mitigate dendritic growth.