Shear band morphology of indented region in Cu-based metallic glass

Plastic deformation after indentation of the metallic glass Cu₄₇Ti₃₅Zr₁₁Ni₆Si₁ at different loading conditions was examined. Discontinuities on the loading curves were observed, the magnitude of which depends on the loading rate. The presence of these discontinuities is influenced by the precise shape of the indentation tip. At lower loading rates and using a cube corner indenter tip the discontinuities on the loading curves are more pronounced. An increase of the loading rate tends to diminish instantaneous plastic deformation as appear by pop-ins. Using a Berkovich type indenter tip the plastic deformation is more steady. It is concluded that the final morphology of the pile-up area strongly depends on the geometry of the indenter tip, whereas no correlation between discontinuities in the loading part of the indentation curve and the formation of shear band patterns was observed.