Deformation behavior and fracture of Al-CuZr nano-laminates: A molecular dynamics simulation study

Abstract

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 Å × 50 Å × 15 Å 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 nanocrystalline 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