Deformation and Fracture Behaviors of Zr-based Metallic Glasses under Different Constraint Shear Angles

The deformation and fracture behaviors of Zr35Ti30Be27.5Cu7.5 metallic glasses (MGs) under different shear angles were systematically investigated via shear tests with different constraint shear angles of 30 degrees, 45 degrees and 60 degrees. The fracture strength of the MGs subjected to constraint shear tests increases gradually with increasing shear angles. This positive relationship between the fracture strength and the applied shear angles was verified by the Mohr-Coulomb criterion, suggesting a good agreement between experimental results and theoretical predictions. Due to the large shear stress, the content of free volume generation is greater than the content of free volume annihilation in MGs with the small constraint shear angles and then, a large amount of free volume aggregates to form multiple shear bands, manifesting as a large number of serration events. The formation and interaction of multiple shear bands can prevent the shear bands from rapidly expanding into cracks, significantly improves the plasticity of MGs.