Flow serration and shear-band propagation in bulk metallic glasses

Flow serration in bulk metallic glasses (BMGs) was analyzed using high-sensitivity strain gauges. Based on the displacement-time profile for one serration, shear-band propagating speed was determined and found to be insensitive to the applied strain rates. The disappearance of serration at high strain rates is a result that the signal of displacement burst was overwhelmed by the applied strain rate. In comparison with the ductile Pd-based and brittle Mg-based BMGs, the ductility of BMGs appears to be closely related to the dynamics during shear-band propagation.