Power-law scaling between mean stress drops and strain rates in bulk metallic glasses

Discrete, jerky stress-drop bursts (serrated flows) during plastic deformation of a Zr-based bulk metallic glass exhibit different magnitudes in response to variant strain rates. Through the classical statistical analysis of stress-strain curves during serrated flow, plastic dynamic behavior changes from Gauss to the power-law distribution with increasing the strain rates. In addition, a quantitative liner relation between mean stress drops and the logarithm of strain rates is obtained to describe the influence of strain rates on mean amplitudes of the stress drop. The power-law scaling behavior is illustrated in different views including the strain-rate dependence, energy dynamics, the Poisson's ratio of material, and shear-banding operation. These results are helpful for understanding the serration behavior at room temperature.