Imparities of shear avalanches dynamic evolution in a metallic glass

Abstract

The imparities of shear avalanches dynamic evolution under nanoindentation originating from the soft regions and the stiff matrix were explored in a metallic glass by statistical and dynamic analysis. Upon the continuous indentation process, the dynamic state of the stiff matrix exhibits a transition from a chaotic behavior to a self-organized critical (SOC) behavior, whereas the soft regions are dominated by the SOC behavior throughout the indentation process. The mechanism was clarified by the evolution of the cut-off size of shear avalanches. These findings might advance our fundamental understanding of inhomogeneous deformation on microscale. Impact statement: The shear avalanches dynamic evolution controlled by the atomic-scale rearrangement mechanism in metallic glasses strongly relies on the structural state and the history of deformation.