High-throughput laser-driven micro-flyer spall failure investigations of ECAE-processed Mg-Al alloys  

Measuring and understanding the dynamic failure mechanisms of materials based on microstructural observations is paramount in our effort to design materials from the ground up with predictive and tailored properties.  This necessitates the use of reliable high-throughput material testing systems and methods. Herein we explore a simple binary alloy material system, Mg-Al, by utilizing a high-throughput Laser-Driven Micro-Flyer (LDMF) experiment to study the spall failure process as a function of composition and microstructure. Improving the spall strength of Mg Alloys is of particular interest for protection-based applications due to its high specific strength. We explore two compositions, Mg-6Al and Mg-9Al, that are each processed through two distinct routes via Equal Channel Angular Extrusion (ECAE) in order to achieve (1) a finer and more equiaxed precipitate structure and (2) a reduced grain size. LDMF experiments are carried out to measure the spall strength at high strain rates (~10^6 s-1) in all three material directions for all four sample sets with 30+ tests for each set (360+ data points in total). Our analysis focuses on understanding the spall strength as a function of the composition and microstructure.