New evidences for understanding the serrated flow and shear band behavior in nanoindentation of metallic glasses

Nanoindentation of a Zr-based metallic glass was performed under various loading rates by using a cube-corner indenter. Experimental results showed that increasing the loading rate from 2 to 20 mN/s, the size of serrated flow was greatly weakened, but the number of serrated flow kept very stable, together with very similar shear band features around the residual indents. These results challenge the current understanding derived from the results obtained by using the Berkovich indenter, and can be well explained by the shear-band propagation dynamics model, i.e., loading rate impeded the propagation of shear band rather than its nucleation. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Nanoindentation experiments were conducted on a Zr-based metallic glass under various loading rates, revealing that increasing the loading rate weakened the size of serrated flow but kept the number stable, while maintaining similar shear band features around residual indents. These results challenge the previous understanding derived from experiments using the Berkovich indenter.