Temperature-Dependent Configurational Entropy Calculations for Refractory High-Entropy Alloys
Temperature-Dependent Configurational Entropy Calculations for Refractory High-Entropy Alloys
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DOI：
10.1007/s11669-021-00879-9
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发表时间：
2021-04
影响因子：
1.4
通讯作者：
Chiraag M Nataraj;A. van de Walle;A. Samanta
中科院分区：
文献类型：
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作者：
Chiraag M Nataraj;A. van de Walle;A. Samanta
用合金的团簇展开形式构造了三种高熵难熔合金（NbTiVZr，HfNbTaTiZr和AlHfNbTaTiZr）的替代模型。这些集团膨胀模型，然后使用沿着与Monte Carlo方法和热力学积分计算这些难熔高熵合金的构型熵作为温度的函数。许多固溶体合金设计准则是基于理想混合熵，其随着合金中元素的数量单调增加。然而，我们的研究结果表明，在低温下，这些材料的构型熵在很大程度上是独立的，上述假设只适用于高温极限。这表明基于理想混合熵的合金设计准则需要进一步研究。
The cluster expansion formalism for alloys is used to construct surrogate models for three refractory high-entropy alloys (NbTiVZr, HfNbTaTiZr, and AlHfNbTaTiZr). These cluster expansion models are then used along with Monte Carlo methods and thermodynamic integration to calculate the configurational entropy of these refractory high-entropy alloys as a function of temperature. Many solid solution alloy design guidelines are based on the ideal entropy of mixing, which increases monotonically with, the number of elements in the alloy. However, our results show that at low temperatures, the configurational entropy of these materials is largely independent of, and the assumption described above only holds in the high-temperature limit. This suggests that alloy design guidelines based on the ideal entropy of mixing require further examination.