Amy J. Clarke¹, Benjamin Ellyson¹, John Copley¹, Francisco Coury², Jonah Klemm-Toole¹, Yaofeng Guo¹, Jinling Gao³, Chandler Gus Becker¹, Brian Milligan¹, Christopher Finfrock¹, Chloe Johnson¹, Kester Clarke¹, Wayne Chen³, Niranjan Parab⁴, Tao Sun⁴, Kamel Fezzaa⁴; ¹Colorado School of Mines, ²Universidade Federal de São Carlos, ³Purdue University, ⁴Advanced Photon Source, Argonne National Laboratory

TRansformation Induced Plasticity (TRIP) and TWinning Induced Plasticity (TWIP) are deformation mechanisms commonly employed in the design of Advanced High Strength Steel (AHSS) microstructures that exhibit desirable combinations of strength and ductility for crash management in automotive applications. Yet, these deformation mechanisms are underutilized and less understood in lightweight metallic alloys such as Ti, important for aerospace, defense, and biomedical applications. Here we use in-situ imaging and diffraction at the Advanced Photon Source at Argonne National Laboratory to study TRIP/TWIP behavior in metastable beta-Ti and multi-principal element alloys (MPEAs) during dynamic loading in tension and compression at strain rates up to approximately 10³ s^-1. Quasi-static and intermediate strain-rate testing and detailed microstructural characterization are also performed to support the development of experimentally-validated modeling. Fundamental understanding of TRIP/TWIP will enable novel alloying and processing strategies to create microstructures and properties by design for performance (e.g. blast resistance) in extreme environments.