Structural Mechanisms of the Cooling Rate Effect on the Deformation Behaviors in Metallic Glasses

Abstract

In this work, the structural mechanisms of the cooling rate effect on the deformation behaviors in metallic glasses (MGs) is studied, by performing the synchrotron radiation-based experiments coupled with a series of simulations. It is found that a MG prepared at lower cooling rate has the higher yield strength and is more likely to soften itself, resulting in lower plasticity. This is because some atomic-to-cluster level structural factors, such as coordination numbers, atomic packing efficiencies, cluster concentrations and regularities. In addition, a quantitative analysis reveals that higher cooling rate leads to more free volumes, and significantly affect the evolution of free volumes during the compressive deformation, tuning the formation and the evolution of shear transformation zones, as well as the yield strength and the plasticity.