Strain rate effects on the deformation behavior of (Zr55Al10Ni5Cu30)99Y1 and Cu45Zr47.5Ag7.5 bulk metallic glasses

The strain rate effects on the deformation behavior of bulk-metallic glasses (BMGs) are investigated. The loading-unloading-reloading tests were performed with the same strain rates for the loading and reloading. The deformation for both (Zr55Al10Ni5Cu30)99Y1 and Cu45Zr47.5Ag7.5 BMGs shows the strain softening at the low strain rate. However, at the high strain rate, the (Zr55Al10Ni5Cu30)99Y1 BMG exhibits more obvious strain softening while Cu45Zr47.5Ag7.5 BMG demonstrates the strain hardening instead. This could be rationalized by the free volume increase and the structural instability during plastic deformation process.