Tailored hardening of ZrCuAl bulk metallic glass induced by 2D gradient rejuvenation

Abstract

Abstract The work hardening behavior of bulk metallic glasses has not been previously ascribed to their intrinsic structure but rather to the introduction of other components that act as hardening elements. Here, we present clear evidence of a 2D gradient rejuvenation state that can induce tailored hardening of a monolithic bulk metallic glass. We show that the local free volume content related to the rejuvenation state controls the shear band angle and the maximum effective shear stress. Hence, shear band propagation is prohibited, and the formation of a complete shear plane transecting the whole specimen is blocked. The generation of plastic strain is accompanied by an increase in the critical shear stress, resulting in sustainable apparent hardening. In this way, we present a bulk metallic glass that has a tailored hardening mechanism and establish an experimental link between a gradient rejuvenation state and mechanical properties.