Effect of the nanoindentation rate on the shear band formation in an Au-based bulk metallic glass

This study investigated the nanoindentation behavior of Au49Ag5.5Pd2.3Cu26.9Si16.3 bulk metallic glass samples at loading rates ranging from 0.03 to 300 mN s−1. Notable shear band pop-in events were observed. The pop-in size was observed to increase linearly with the load and decreased exponentially with the strain rate. A free-volume mechanism was proposed for interpreting these observations quantitatively. The results and analyses also shed light on the shear band nucleation and evolution processes in bulk metallic glasses.