Billy Hornbuckle¹, Xuyang Zhou², Cyril Williams¹, Steven Dean¹, Anit Giri¹, Anthony Roberts¹, Greg Thompson², Kiran Solanki³, Kris Darling¹; ¹US Army Research Laboratory, ²The University of Alabama, ³Arizona State University

The ability to evaluate a nanocrystalline material under extreme states of stress experienced in a shock experiment were once thought to be impossible. However, with the development of thermally and mechanically stable nanocrystalline alloys, this impossibility is now a reality. A nanocrystalline Cu-3Ta (At.%) alloy, that has been shown to be both thermally and mechanically stable, had shock recovery test performed on a 10 mm diameter specimen. This work reports the changes in hardness and microstructure of the Cu-3Ta alloy post mortem after undergoing shock compression up to 15 GPa. Scanning transmission electron microscopy (STEM) coupled with precession electron diffraction provide insight into the changes in grain size and texture of the initial microstructure as well as the dislocation density and other deformation mechanisms present.