Date:
Monday, February 24, 2020
Time:
8:00 a.m. to 11:30 a.m.
Location:
San Diego Convention Center, Room 6C
Sponsored by:
TMS Light Metals Division, TMS Magnesium Committee
Organizers:
J. Brian Jordon, University of Alabama; Victoria Miller, University of Florida; Vineet Joshi, Pacific Northwest National Laboratory; Neale Neelameggham, IND LLC
The Magnesium Technology 2020 symposium at the TMS 2020 Annual Meeting & Exhibition will open with a session of invited presentations on Monday morning. Following the keynote, related sessions will be held throughout the week as part of the Magnesium Technology symposium, one of the largest annual gatherings of magnesium specialists in the world. Learn more about the Magnesium Technology 2020 symposium.
Featured Speakers
Carlos Tome, Los Alamos National Laboratory, USA
Presentation Title: "Twin Transmission Across Grain Boundaries in Magnesium"
About the Presentation
Transmission of {1012}〈1011〉 mechanical twins across grain boundaries in magnesium is a mechanism that can facilitate intergranular crack propagation by providing a path to cracks along the twin interface. Until now, the focus has been on a 2D characterization of twin transmission along the forward propagation direction. Recent 3D studies of the twin domain interface reveal anisotropic mobility and a relative easiness of lateral twin propagation as opposed to forward or normal propagation. Here we study the forward and the lateral twin transmission into neighbors applying a variety of experimental and computational characterization techniques, namely: (1) statistical EBSD analysis of twin sections; (2) Phase Field simulations of twin growth; (3) 3D Molecular Dynamic simulations of twins reacting with grain boundaries. This study improves our understanding of the transmission mechanisms in a 3D aggregate and helps us to develop criteria for treating twin modeling in CP simulations.
About the Presenter
Carlos N. Tomé joined Los Alamos National Laboratory in 1996 as a scientist, and he is currently a laboratory fellow. Prior to joining Los Alamos, he was a professor at the National University of Rosario (Argentina) and scientific staff member at Atomic Energy of Canada. For the past 35 years, his research interest has been on elastic, plastic, and creep behavior of polycrystalline aggregates, specifically, the development of constitutive equations at the single crystal level for low symmetry metals and geologic materials. His research includes pioneering the theoretical and numerical modeling of mechanical behavior of polycrystals, with a focus on the role played by texture, twinning, and microstructure.
Tomé has over 210 peer-reviewed publications, with 22,000 citations and h-index=71. He has co-authored the books, Texture and Anisotropy and Fundamentals and Engineering of Severe Plastic Deformation. He received the 2013 Distinguished Scientist/Engineer Award, and the 2016 Cyril Stanley Smith Award, both awarded by TMS.
Rajiv Mishra, University of North Texas, USA
Presentation Title: "Hierarchically Structured Ultrafine Grained Magnesium Alloys"
About the Presentation
The intrinsic low density of magnesium drives research towards high performance magnesium alloys. Hierarchically structured ultrafine grained magnesium alloys possess exceptional strength-ductility combination and eliminate many of the traditional drawbacks like low strength, high yield strength asymmetry, poor formability, and limited superplasticity. In this overview presentation, friction stir processed microstructures are used as examples to discuss the microstructural paradigms that can exhibit an excellent balance of mechanical properties. These show the possibilities of exceeding 500 MPa strength with good work hardening and >10% ductility. Use of micron-sized boron carbide (B4C) and nano-sized yttria (Y2O3) powder can simultaneously enhance modulus-strength-ductility combination. High strength ultrafine grained magnesium alloys also show high strain rate superplasticity which can provide pathways for overcoming poor formability. An example of friction stir additive manufacturing will be used to discuss possibilities of implementing such microstructures at component level with emerging solid-state additive manufacturing techniques.
About the Presenter
Rajiv S. Mishra (Ph.D. in Metallurgy from University of Sheffield) is a university distinguished research professor at the University of North Texas (UNT). He serves as the director of the Advanced Materials and Manufacturing Processes Institute (AMMPI) at UNT. He is also the director of the NSF I/UCRC for Friction Stir Processing and a Fellow of ASM International. He is a past-chair of the Structural Materials Division of TMS and served on the TMS Board of Directors (2013 to 2016). He has authored/co-authored >375 papers in peer-reviewed journals and proceedings and is principal inventor of four U.S. patents. His current publication-based h-index is 63 and his papers have been cited more than 21,000 times. He has co-authored two books; (1)
Friction Stir Welding and Processing, and (2)
Metallurgy and Design of Alloys with Hierarchical Microstructures. He has co-edited fifteen TMS conference proceedings. He is an Associate Editor of
Journal of Materials Processing Technology and serves on the editorial boards of
Materials Science and Engineering-A,
Science and Technology of Welding and Joining, and
Materials Research Letters. He is the founding editor of a short book series on Friction Stir Welding and Processing published by Elsevier and has co-authored seven short books in this series.
Mark Horstemeyer, Liberty University, USA
Presentation Title: "MultiStage Fatigue (MSF) Modeling of Magnesium in a Corrosion Environment"
About the Presentation
This work presents an overview of using the MultiStage Fatigue model with a corrosion model to capture the behavior of magnesium alloys. One can argue that magnesium alloys used for structural components are always in a corrosive environment as no real practical structural component operates in a vacuum. As such, different magnesium alloys are analyzed in the context of their fatigue incubation, Microstructurally Small Crack (MSC), and long crack regimes under a vacuum, air, and salt-water environments. The different magnesium alloys analyzed include AE44, AM30, AM50, AM60, AZ31, AZ61, and AZ91 alloys. These alloys were fabricated under different methods, and each had different heat treatments. The levels of corrosion pitting, general corrosion, and filiform corrosion were quite different for each alloy, meaning that the interdependence of the different corrosion mechanisms interacted differently with each alloy’s incubation, MSC, and LC fatigue lives. These points will be delineated and explained in this presentation.
About the Presenter
Mark F. Horstemeyer joined Liberty University as the Dean of Engineering in January 2019, bringing 30 years of industrial, national laboratory, and academic experience after working at Owens Corning Fiberglas, Sandia National Labs, and Mississippi State University. Horstemeyer is a fellow in the American Society of Mechanical Engineers, American Society of Metals, Society of Automotive Engineers, and the American Association for the Advancement of Science. He also is a member of the National Academy of Engineering in the European Union. He has demonstrated strong leadership in creating and implementing multiscale modeling strategies into the research and academic process. He has published over 500 journal articles, conference papers, books, and technical reports with a citation impact h-factor of over 60 with over 12,000 total citations; he has been invited to give over 150 lectures throughout the world and has mentored over 150 graduate students and post-doctoral researchers.
Bin Jiang, Chongqing University, China
Presentation Title: "Novel Texture Controlling of Mg Alloys"
About the Presentation
Conventionally extruded Mg alloy sheets possess poor mechanical properties due to the strong basal texture. This brings about a poor deformation capability of sheet thinning and a stronger anisotropy and consequently results in limited number of available plastic deformation modes. In this work, a novel extrusion approach to get high strength magnesium alloy plates will be introduced. A suitable constitutive model of differential speed extrusion is established to ameliorate the texture-dependent mechanical properties. The yield stress of AZ31 alloy sheet has been increased from 161.2 MPa to 179.9 MPa and the elongation has been improved from 15.4 % to 20.1 %. AZ61 alloy sheets’ ultimate tensile strength was increased from 387.9 MPa to 427.1 MPa and the yield stress was improved from 147.7 MPa to 195.9 MPa. Grain refinement and tilted weak basal texture obtained by differential speed extrusion process.
About the Presenter
Bin Jiang graduated from Chongqing University and received his Doctor’s degree in 2003. He is a professor in Chongqing University and head of the Materials Science Department of Materials Science & Engineering College, vice director of National Engineering Research Center for Magnesium Alloys (CCMg). Jiang mainly devoted himself to research on wrought magnesium alloys and has published over 120 research papers and has been granted over 40 Chinese patents.