Insights from the MEDE program: An overview of microstructure–property linkages in the dynamic behaviors of magnesium alloys

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Magnesium (Mg) and its alloys have been the subject of intensive scientific research and development in the communities of materials science and engineering, mechanical engineering and manufacturing. Considering their light weight and high specific strength, current and potential applications include the aerospace industry, automobiles, and vehicle and personnel armors. This range of applications demands a good understanding of the behavior under extreme conditions such as impact or high strain rate loading. The past two decades have witnessed a surge of studies of the mechanical responses of Mg and its alloys under impact loading, both experimentally and using simulations and modeling at different spatial and temporal scales. Experimental examinations at strain rates up to 107 s−1 (shock wave loading) have been published. In terms of simulations and modeling efforts, multi-physics, multi-scale investigations, from first principles calculations (density functional theory, DFT), molecular dynamics (MD), discrete dislocation dynamics (DDD), crystal plasticity (CP) and continuum mechanics have all been explored. To address the challenges in design, manufacturing and application of Mg alloys, the US Army Research Laboratory (US-ARL) created the Materials in Extreme Dynamic Environments (MEDE) Collaborative Research Alliance (CRA) in 2012. The goal of the Metals Program within the MEDE CRA has been to observe, understand, and design the mechanisms active within Mg and Mg alloys in these extreme conditions.In this paper, fundamental aspects of plastic deformation of Mg and Mg-alloys and the history of the research efforts in experiments, modeling, and simulations available in the literature are critically reviewed. Key findings and contributions from the Materials in Extreme Dynamic Environments (MEDE) Metals Collaborative Materials Research Group (CMRG) are presented, followed by summary and future perspectives.