First-principles calculations to investigate phase stability, elastic and thermodynamic properties of TiMoNbX (X=Cr, Ta, Cr and Ta) refractory high entropy alloys

This work uses first-principles calculations to investigate the phase stability, thermophysical and mechanical properties of refractory high entropy alloys (RHEAs) at finite temperatures. On the basis of plane wave quasi-potential and density functional theory, construct the structure model of a solid solution. The TiMoNbX (X = Cr, Ta, Cr and Ta) RHEAs have been determined to preserve a single body-centered cubic solid solution structure by calculations and the equilibrium lattice parameters and elastic modulus are consistent with experimental data obtained by laser cladding, which is combined with TC4 (Ti-6Al-4V) substrate. Using the quasi-harmonic Debye-Grüneisen model, the thermophysical characteristics of three RHEAs are investigated. The Voigt-Reuss-Hill scheme is used for calculating the Young's modulus (