Study on stochastic nature of plasticity of Cu/Zr metallic glass micropillars

Micro-sized metallic glass pillars with a diameter ranging 2.5∼7.5 μm were subjected to compression experiments using a nanoindentation tester equipped with a flat punch, to characterize their deformation behaviors. The strain-stress response and scattering mechanical properties were studied in statistics. The intermittent and trigger-aftershock shear avalanches exhibited a stochastic nature of plasticity of metallic glass specimens under microscale. The size distribution of strain bursts versus the stress where they occurred indicated the flow dynamics as a self-organized behavior with collective motion of multiple shear bands, and the maximum burst size increased with applied stress following in a power-law manner independent of burst order and pillar size. According to the experimental observation, universal features were proposed to characterize the current jerky deformation, meanwhile a Monte Carlo simulation method was developed to predict the stochastic plasticity of metallic glass under microscale. •CuZr-based metallic glass micropillar suffers from intermittent shear bursts.•Size distribution of strain bursts vs. stress is investigated in statistics.•Self-organized critical behavior of metallic glass micropillar shows a size effect.•Universal features are proposed to characterize the current jerky deformation.•Monte-Carlo simulation is performed to verify the stochastic nature of metallic glass.