Dual character of stable shear banding in bulk metallic glasses

In this work, a systematical study of the stable shear banding behavior is performed across a wide range of alloy compositions of bulk metallic glasses (BMGs). Through microcompression, it can be demonstrated that the stable shear banding behavior could exhibit a dual character of stochastic and deterministic propagations. Different from the stochastic character, which is found insensitive to sample sizes, the deterministic character displays a clear trend of a sample size effect, which can be captured by the energy balance principle. Based on the theoretical framework laid out in this work, a correlation between the plastic energy dissipation and the sample size effect is established, which can be then utilized to explore the influence of the alloy's chemical compositions on the behavior of shear-induced material softening. Finally, the energy-based formalisms aimed to quantify the shear banding size effect in MGs are discussed. © 2011 Elsevier Ltd. All rights reserved.