Structural evolution and energy landscape of Zr55Cu35Al10 ternary alloy during glass transition

Abstract

In this work, classic molecular dynamics simulations were employed to study the glass transition of Zr55Cu35Al10 ternary alloy. According to the structure and energy analysis, during quenching to the glass transition temperature (Tg) of the Zr55Cu35Al10 alloy, by quantitatively analyzing the cluster, i-zone and free volume atom pairs based on the tight-bond cluster model, it was found that the fraction of the cluster and i-zone atom pairs increased while the fraction of the free volume atom pairs decreased continuously. The Zr-centered first shell clusters tend to transform to the coordination polyhedra with high coordination number (CN) owning low cluster energy and the Cu- and Al-centered clusters tend to become the coordination polyhedra with CN = 12 presenting the lowest cluster energy in the short-range structure. The medium-range structure of the coordination polyhedra connection sharing three atoms with the lowest energy increased significantly. Furthermore, it was confirmed that the significance of Al addition on the increase in glass forming ability (GFA) in the ZrCuAl ternary alloys.