Effect of residual shear bands on serrated flow in a metallic glass

This work studies the effects of the shear bands on serrated flow of the metallic glass Zr–5Ti–17.9Cu–14.6Ni–10Al using nanoindentation technique and scanning electronic microscopy (SEM). It was observed that the nanoindentation load–displacement (P–h) curves are serrated when the nanoindents were made within the region had pre-introduced shear bands from a spherical indentation made with higher load in the specimen. The results support the earlier observation and assumption that the pre-introduced shear bands intersect with the new shear bands induced by nanoindentations, leading to less pile-up around the nanoindentation impressions. This result is discussed with possible mechanisms of the plastic deformation of the metallic glass materials.