Correlation Between Plasticity and Atomic Structure Evolution of a Rejuvenated Bulk Metallic Glass

Abstract

This article aims to establish a relation between the excitation of atomic structure, namely rejuvenation, and plasticity behavior of a Zr-based bulk metallic glass (BMG). The synchrotron X-ray diffraction (XRD) results showed that the cryothermal treatment leads to rejuvenation of the material, which is manifested by the structural disordering and the rearrangement of atomic clusters. It was also revealed that the rejuvenated structure provides more potential sites for shear-banding events during compressive loading. Hence, the homogeneous plasticity improves in the rejuvenated samples, which is recognized by a self-organized critical state of serrations in the stress–strain curves and high population of shear bands on the lateral surface of samples. On the other hand, a high energy barrier for shear transitions in as-cast specimens led to a semi-brittle failure with low plastic deformation. In general, with the increase in the number of cryothermal cycles, the rejuvenation as well as the non-localized deformation enhances in the BMG.