Temperature dependence of mechanical and thermodynamic properties of refractory high entropy alloys Ti_(25+x)Zr₂₅Nb₂₅Ta_(25-x) (x ≤ 20) are studied from ab initio quasi-harmonic Debye-Grüneisen model, and the influences of substitution of Ti for Ta are emphasized. The substitution of Ti for Ta results in the significantly reduced densities and the apparently enhanced specific elastic properties of Ti_(25+x)Zr₂₅Nb₂₅Ta_(25-x) alloys. Moreover, the increases of Ti content obviously improves ductility. At high temperature, the alloys with higher Ti content demonstrate the stronger thermal expansion behavior and thermal conductivity. Importantly, the alloys with higher Ti content possess the greater specific elastic properties at high temperature. Especially, in the studied temperature range, the present alloys exhibit good anti-softening ability based on temperature-dependent mechanical properties. Therefore, the replacement of Ta by Ti in refractory Ti_(25+x)Zr₂₅Nb₂₅Ta_(25-x) alloys is beneficial for formation of novel high temperature light-weight structural materials with lower density, better ductility and higher specific mechanical properties.

从头算准谐波Debye-Grüneisen模型研究了难熔高熵合金Ti _{（25 + x）} Zr ₂₅ Nb ₂₅ Ta _（25-x）（x≤20）的力学和热力学性质与温度的关系，以及强调了用Ti代替Ta。用Ti代替Ta会导致密度显着降低，并且Ti _{（25 + x）} Zr ₂₅ Nb ₂₅ Ta _{（25-x）的}比弹性明显增强。合金。而且，Ti含量的增加明显改善了延展性。在高温下，Ti含量较高的合金表现出更强的热膨胀性能和导热性。重要的是，具有较高Ti含量的合金在高温下具有较大的比弹性。特别是，在所研究的温度范围内，基于温度的机械性能，本发明合金表现出良好的抗软化能力。因此，在难熔Ti _{（25 + x）} Zr ₂₅ Nb ₂₅ Ta _（25-x）合金中用Ti代替Ta有利于形成密度较低，延展性更好和比机械性能更高的新型高温轻质结构材料。属性。