Development of a semi-empirical interatomic potential appropriate for the radiation defects in V-Ti-Ta-Nb high-entropy alloy

Abstract

High-entropy alloys (HEAs) hold promise as candidate structural materials in future nuclear energy systems. Body-centered cubic V-Ti-Ta-Nb HEAs have received extensive attention due to their excellent mechanical properties. In this work, the Finnis-Sinclair interatomic potential for quaternary V-Ti-Ta-Nb HEAs has been fitted based on the defect properties obtained with the density functional theory (DFT) calculations. The new potential for Nb accurately reproduces the vacancy formation energy, vacancy migration energy and interstitial formation energy. The typical radiation defect properties predicted by the alloy potential were consistent with the DFT results, including the binding energies between substitutional solute atoms, the binding energy between substitutional atoms and vacancies, and the formation energy of interstitial solute atoms. In addition, the mixing enthalpies of the alloys were also consistent with the DFT results. The present potential can also describe reasonably the cascade collision process of quaternary V-Ti-Ta-Nb HEAs.

Studying Plastic Deformation Mechanism in β-Ti-Nb Alloys by Molecular Dynamic Simulations

“…In this study, we employed the FS atomic potential developed by Qiu et al [25] for the four-element V-Ti-Ta-Nb high-entropy alloy. This potential was fitted based on density functional theory (DFT) calculations of defect properties, including vacancy formation energy, vacancy migration energy, and interstitial formation energy.…”

“…However, the available potential functions for the Ti-Nb system are relatively limited. This study utilized the semi-empirical Finnis-Sinclair (FS) potential, which Qiu et al [25] employed for V-Ti-Ta-Nb high-entropy alloys. This potential has demonstrated accurate predictions of properties related to typical radiation defects and mixing enthalpy, aligning well with theoretical values.…”