Ab initio molecular dynamics study of TiZrNbHfTa and VZrMoHfW liquid alloys

Abstract

The structural and dynamical properties of liquid alloys are directly related to their solidification process, and consequently to the properties of as-cast solid alloys. Ab initio molecular dynamics is a powerful tool that can be used to study both of these factors. Thus, in this work, TiZrNbHfTa and VZrMoHfW liquid equiatomic alloys, exclusively consisting of transition metal (TM) elements, are studied using ab initio molecular dynamics via the CP2K software package; partial-pair correlation functions (PPCFs) are calculated, and their parameters are discussed. The calculated densities of these alloys are shown to be close to the ideal mixture densities. The analysis of the PPCFs is performed to predict the single-phase high-entropy alloy (HEA) formation. The obtained results agree with the semi-empirical phase formation rules. The diffusivities of the elements are calculated using the Green–Kubo relation and the mean square displacement (MSD) plot. The diffusivity is shown to decrease as the atomic mass and radius increase. The scattering process of different types of atoms in TiZrNbHfTa and VZrMoHfW are also discussed.