Structural heterogeneity originated plasticity in Zr-Cu-Al bulk metallic glasses

The brittleness at room temperature has become the major issue for bulk metallic glasses (BMGs) as structural engineering materials and a significant challenge is to improve and research the plasticity. Study on structural heterogeneity may be a key to understand the origin of plasticity in BMGs. In the current research, correlation of plasticity with structural heterogeneity which is studied by beta-relaxation, fragility, serration dynamics, and free volume has been studied in a Zr-Cu-Al BMGs system. These quantities are unified with each other. It has evidenced that the degree of beta-relaxation behavior has a close correlation with the plasticity and fragility. A good plastic deformation in BMG has a more heterogeneous serrations with a higher serration barrier. Compared with a poor plasticity BMG, the ductile has a more heterogeneous structure with more free volume. All of these can owe to the structural heterogeneity originated plasticity. This finding is believed to have implications for understanding the origin of plasticity from the perspective of structural heterogeneity in BMGs.