Plastic flow in dynamic compression of a Zr-based bulk metallic glass

Using geometrically constrained specimens, the plastic flow behaviors of the as-cast and the relaxed Zr_52.5Cu_17.9Ni_14.6Al_10.0Ti_5.0 bulk metallic glass in the dynamic compression were investigated. Both alloys exhibit a significant plasticity in the dynamic compression. The plastic deformation in both alloys is still inhomogeneous, which is characterized by the serrated plastic flow and the formation of shear bands. Free volumes affect the shear banding and the plastic flow. The reduced free volume results in the deviation of the shear banding direction from the maximum shear stress. The relaxed alloy exhibits the obvious stress overshoot, which is consistent with the theoretical prediction using a free volume model.