Deformation Behavior and Fracture of Al-CuZr Nano-Laminates: A Molecular Dynamics Simulation Study

Abstract

In this paper, we report classical molecular dynamics (MD) simulation deformation studies and fracture behavior of nano-crystalline Al (metal)-Cu50Zr50 (metallic glass) nano-laminates. The samples for the above studies consist of alternate layers of nano-crystalline aluminum and Cu50Zr50 metallic glass (MG). The nano-laminates models of 150 A × 50 A × 15 A have been constructed by taking Al and Cu50Zr50 MG of three different widths ranging from 1 nm–5 nm. The Cu50Zr50 MG is prepared by randomly generating the coordinates and replacing 50% copper atoms by zirconium atoms. EAM (Embedded Atom Method) potential is used for modeling the interaction between Al-Cu-Zr atoms. The models are deformed at a temperature of 300 K and strain rate of 1010 s−1 under mode-I loading conditions. Periodic boundary conditions are applied along the loading direction, while non-periodic along the thickness and width. It is observed that with an increase in width of the MG the nano-laminates strength increases (1.8 GPa). Ductile facture is observed in all the models. The grain boundary process is found to be active in pure nano-crystalline Al while it is insignificant in the laminates. Amorphization is observed in all the laminates at larger strains. The present study gives a significant insight into nano-laminates deformation behavior and underlying mechanism and at metal-metallic glass interface.