Determination of parameters of free volume model for Zr-based BMG via nanoindentation

The mechanical behavior of Zr55Cu30Ag15 bulk metallic glass (BMG) was investigated via the free volume theory. Spherical and Berkovich nanoindentation tests were conducted, and corresponding finite element models were constructed by implementing a pressure-dependent free volume model based on user material subroutine (UMAT). By performing a sensitivity study, two model parameters were selected as decisive parameters. Unlike Drucker-Prager model, the implemented free volume model properly describes (i) load-depth response and (ii) sub-indenter shear band and softening behavior from both spherical and Berkovich nanoindentations.

Automated summary

The mechanical behavior of Zr55Cu30Ag15 bulk metallic glass was studied using the free volume theory, with experiments and finite element models showing the advantages of the implemented model. Two key model parameters were identified through sensitivity studies, highlighting the effectiveness of the pressure-dependent free volume model in describing load-depth responses and shear band behavior in nanoindentation tests.