On the stress-state dependent plasticity of brittle metallic glasses: Experiment, theory and simulation

In this work, the stress-state dependent plasticity of brittle Ti-based metallic glass was investigated by experiment, mechanics theory and simulation systematically. With different settings of arc-shaped edges, various stress gradients could be generated artificially. The systematical work showed that the global plastic deformability of a metallic glass depended strongly on the stress states under compressive loadings. By introducing the Mohr-Coulomb yielding criterion and the associated flow rule, we proposed an elastic-plastic model to analyze the deformation behaviors of all specimens. Combined with the experimental results and the numerical results by finite element method (FEM), it was demonstrated that the present simulation model could suitably describe the plastic deformation process of the specimens, and the different stress states might have a vital significance on the global plastic deformation behavior. The current results and analytical model could provide an approach to understand the further plastic deformation mechanism of brittle metallic glasses with different stress states.