Size-affected shear-band speed in bulk metallic glasses

Abstract

In this letter, we report an important experimental finding and theoretical analysis of the shear-band speed measured in a variety of bulk metallic-glasses. Unlike the prior work, in which the shear-band speed was regarded as a constant, our current study, based on carefully designed loading-holding cyclic tests, reveals that the speed of a shear band correlates with its resultant shear offset. Such a correlation arises as a “size” effect, which could be rationalized with the energy balance principle and shear-banding dynamics entailing initial shear softening and subsequent materials recovery.