Imparities of shear avalanches dynamic evolution in a metallic glass

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. 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.