Molecular dynamics based cohesive zone modeling of Al (metal)-Cu50Zr50 (metallic glass) interfacial mechanical behavior and investigation of dissipative mechanisms

We performed classical molecular dynamics (MD) simulations to predict the strength of Al (metal)-Cu50Zr50 (metallic glass) model interface at a temperature of 300 K and strain rate of 10(10) s(-1) under mode-I and mode-II loading conditions based on the cohesive zone model (CZM). EAM (Embedded Atom Method) potential is used for modeling the interaction between Al-Cu-Zr atoms. It is observed that the interface strength is higher than pure Al, and ruptures in the Al region by necking under mode-I loading. Atoms of Al stick to the Cu50Zr50 metallic glass after fracture due to strong bonding between Al-Cu and Al-Zr atoms than Al-Al atoms as inferred from density functional theory based study. The observed dominant dissipative mechanisms at the interface are partial dislocations and stair rod dislocations under both the loading conditions. The strength of the interface decreases in the presence of a crack as expected. The traction-separation response of the interface shows a maximum stress followed by a decrease in stress indicating the complete separation of the interface. The present study gives a significant insight into metal-metallic glass interface deformation behavior and underlying mechanism. The results can be input into continuum length-scale micromechanical models that determine overall material properties. (C) 2016 Elsevier Ltd. All rights reserved.