Description
The recent development of bulk-metallic glasses makes the applications of metallic glasses as structural materials become a reality. However, the poor ductility and subsequent premature fracture, which are imputed to the highly-localized inhomogeneous deformation, still limit their applications. In spite of intensive studies on the inhomogeneous deformation of metallic glasses for more than 20 years, there are still controversial understandings on its rate dependence. Using an infrared camera, we firstly observe in-situ dynamic shear-banding operations during compression of a bulk-metallic glass at various strain rates. It is demonstrated that the shear-banding events are highly dependent on the strain rates, either intermittent at the lower strain rate or successive at the higher strain rate. Serrated plastic flow is a result of shear banding. These results provide new insights into the rate-dependent shear-banding behaviors.