Capture of shear crack propagation in metallic glass by high-speed camera and in-situ SEM

The dynamic double-notched experiments by using Split Hopkinson Pressure Bars(SHPB) and high-speed camera were performed on bulk metallic glass. In the double-notched experiment, shear crack propagating process was captured with the high temporal resolution of high-speed camera and the crack front propagating velocity was estimated to be 1137m/s. The shear strain/shear stress curve of BMG under dynamic loading was also obtained. Static in-situ SEM tensile experiments were included to study the multiple shear bands propagating behavior on a glassy ribbon. It was found that shear bands propagates progressively in an intermittent and discontinuous manner, and the choice of which shear bands to propagate and which ones to keep still among multiple shear bands is quite stochastic. This is explained qualitatively from the view point of energy.