Enhancing mechanical properties of NbZrMo alloy by maximizing configurational entropy from first-principles calculations

Abstract

High entropy alloys have been widely studied due to their unique physical properties compared to pure metals or conventional alloys with a single principal metallic component. We use ab initio calculations as the most prominent approach to investigate physical properties of materials to study mechanical properties of random ternary alloys NbZrMo. The equation of state and energy-stress relations are fitted to the ground-state energies from density functional theory calculations on structures with randomly arranged atoms on the crystallographic positions of the simple lattices. Among a couple of factors that determine the entropy of structure we consider the configuration that has the main effect on entropy at low temperatures. Several mechanical parameters and moduli are evaluated, and their dependence on the alloy composition is studied. We show that the alloy with the highest configuration entropy possesses the largest Young’s and bulk modulus values. The enhancement of other mechanical properties is also observed.