Monday  |  Salon 13  |  05:10 PM–05:30 PM

#15971, Hypervelocity Impact Experiments on Binary Magnesium Alloys

Magnesium (Mg) alloys are excellent lightweight structural materials, highly abundant in Earth’s crust, possess high specific strength, and have diverse applications in aerospace, defense, and automotive industries. Over the last decade, there has been significant interest in using Mg alloys as protection materials, such as body or vehicle armor, which are often subjected to extreme dynamic conditions. Researchers have focused on elucidating the role of solute concentration, solute type, grain size and texture, precipitates, and other microstructural features on the deformation mechanisms across strain rate regimes and complex shock loading conditions. In this study, we investigated the role of alloying chemistry and precipitates on ballistic performance of three binary Mg alloys: Magnesium–Aluminum (Mg-Al), Magnesium–Zinc (Mg–Zn), and Magnesium–Yttrium (Mg–Y). Ballistic behavior was studied using a canonical sphere-on-plate impact configuration within HyFIRE (Hypervelocity Facility for Impact Research Experiments) setup. Rectangular Mg alloy plates were impacted with 5-mm spheres at low (1.2 km/s) and high (2.4 km/s) velocities. The motions of the rear surface of the impacted plates were measured using high-speed stereo digital image correlation (DIC) at a framing rate of 5 Mfps. The early-time quantitative DIC displacement measurements are correlated with LS Dyna simulations. We have also carried out post-mortem examination of the samples through micro-CT, SEM, and EBSD, to identify the failure mechanisms that control the ballistic performance. Our preliminary analysis shows the invariance of terminal velocity for the same impact velocity for all three binary alloys. However, the hole size and the fracture surface evolution are more prominent in samples with precipitates. These studies demonstrate the complex microstructure-property interrelationships that will likely help advance the materials by design strategy for Mg alloys used in extreme dynamic environments.

Justin Moreno   Johns Hopkins University
Suhas Eswarappa Prameela   Massachusetts Institute of Technology
Pinkesh Malhotra   Johns Hopkins University
Xingsheng Sun Sun   University of Kentucky
Matt Shaeffer   Johns Hopkins University
Timothy Weihs   Johns Hopkins University
KT Ramesh   Johns Hopkins University