Mechanistic origins of work hardening in shape memory alloy particle reinforced ex-situ bulk metallic glass matrix composites

Abstract

All Bulk Metallic Glasses (BMGs) exhibit strain-softening or elastic-perfectly-plastic response under uniaxial loading. However, contrary to expectations, Shape Memory Alloy (SMA) reinforced BMG matrix composites show work hardening behavior in experiments. In this work, we elucidate the mechanistic origins of this work hardening behavior in representative SMA particle-reinforced ex-situ BMG martix composites through three-dimensional Finite Element Simulations. Results suggest that the synergistic effects of a) partial Austenite to Martensite phase transformation, and, b) elastic loading of the transformed Martensite, in the SMA particle, lead to the work hardening in the uniaxial response of the SMA reinforced BMG matrix composites.