Effect of structural heterogeneity on serrated flow behavior of Zr-based metallic glass

Abstract

Physical correlation between structural heterogeneity and plastic flow of metallic glasses (MGs) is crucial for the understanding of MGs' deformation mechanism. In this work, different degrees of structural heterogeneity are introduced into Zr-based MGs through different cooling rates casting. The effect of structural heterogeneity on serrated flow behavior was studied. The findings demonstrate that there exists a tendency that serration flow dynamics of the MGs transforms from a chaotic state to a self-organized critical state with increased inhomogeneity. The established correlation between structural heterogeneity and serrated flow behavior shows that the higher degree of structural heterogeneity facilitates a higher frequency of interaction and multiplication of shear bands by increasing nucleation sites, and then promotes serrated flow behavior to be more homogeneous in time and space, thereby induces transformation of dynamics behavior and improves the plasticity. The obtained results shed light on deformation mechanism of plastic flow and provide a new insight into the plasticity of MGs.