Thermodynamic Properties of Wx(TaTiVCr)1−x High‐Entropy(‐Like) Alloy and Influence of Tungsten Content

Abstract

Based on quasi‐harmonic Debye–Grüneisen model and thermal equation of state, thermodynamic properties of high‐entropy(‐like) alloy Wx(TaTiVCr)1−x (x = 0.30–0.67) phases have been studied by first principles density functional theory calculations combined with special quasi‐random structure (SQS) model, and the influence of W content is predominantly emphasized. Present investigations show that bulk modulus B of Wx(TaTiVCr)1−x declines with increasing temperature, and the softening tendency is similar for various W content, although the strength of Wx(TaTiVCr)1−x demonstrates overall lowering with simultaneous alloying of Ta, Ti, V, and Cr. The thermal expansion coefficient of Wx(TaTiVCr)1−x rises nonlinearly with increasing temperature, and the increase rate is lowered with more W content. The temperature dependence of heat capacity at constant volume CV and constant pressure CP of Wx(TaTiVCr)1−x also exhibits analog behavior at various W content. Thermodynamic entropy of Wx(TaTiVCr)1−x increases dramatically with temperature, and the contribution from electronic entropy, configuration, and vibrational entropy is discussed in detail. In addition, the Debye‐temperature and Grüneisen parameter are also analyzed. The present results are very valuable for optimizing the composition and comprehensive properties of W‐containing high‐entropy(‐like) alloys.