Temperature dependent dynamics transition of intermittent plastic flow in a metallic glass. I. Experimental investigations

摘要

Cooling shrinkage can increase the atomic packing density of metallic glasses, which can influence their elastic and plastic behaviour. In the present study, the compressive deformation behaviour of a Zr-based metallic glass at temperatures well below the glassy transition temperature, say 123 K to room temperature, is experimentally revealed. The elastic modulus and the shear modulus at different temperatures are measured to elucidate the yield strength changes with temperature according to the model of shear transformation zones. In the plastic regime, based on the SEM observation and the digital scattering correlation method, an enhanced interaction between the elastic shear strain fields initiated by neighbouring shear bands is discussed, which explains the amplitude of serration events decreasing with the temperature decreasing.