Elastic and thermal properties of refractory high-entropy alloys from first-principles calculations

Abstract

We present a study of the elastic and thermal properties of single-phase ternary and quaternary Al-Ti-V-Cr-Nb-Mo refractory high-entropy alloys based on the first-principles calculations. The exact muffin-tin orbitals (EMTO) method in combination with the coherent potential approximation (CPA) is employed to calculate the equilibrium bulk properties and elastic parameters. The calculated Young’s moduli are in good agreement with the available experiments. Based on the thermal equation of state we use the quasi-harmonic Debye model to study the thermal properties such as the Gibbs free energy, Debye temperature, thermal expansion coefficient, and specific heat capacity. The elastic moduli at finite temperature are also discussed.