In the study of high-entropy alloys (HEAs), due to the enormous adjustment space of the content (5–35 at.%) of each principal element, the yield strength at room temperature (RT) of the alloys are basically difficult to estimate. Five kinds of Nb-Mo-Ta-W HEAs with the same component elements but in different contents were fabricated by vacuum arc melting (VAM). The crystal structures of five kinds of alloys are all single-phase solid solutions of BCC structure. The grain sizes of each alloy are about ~150 μm and the substructures within the grain are typical dendritic. The calculated yield strength through solid solution strengthening (SSS) model by Senkov is in certain agreement with the experimental yield strength of five alloys. In our study, the concept of configurational entropy is brought in to optimize the model. In comparison with the calculated yield strength of original model, the variation trend curve of the optimized model was in better agreement with that in experiment. Moreover, the optimized SSS model has a certain universality to predict the mechanical properties in other refractory HEAs system with a single BCC structure composed of W, Nb, Mo, Ta, Zr, Hf, Ti, V element. This conclusion provides a theoretical basis for the design of chemical contents of BCC structural refractory HEAs systems.

在高熵合金（HEA）的研究中，由于每种主要元素的含量（5-35 at。％）的调节空间巨大，合金在室温（RT）的屈服强度基本上很难估计。通过真空电弧熔炼（VAM）制备了五种组成元素相同但含量不同的Nb-Mo-Ta-W HEA。五种合金的晶体结构均为BCC结构的单相固溶体。每种合金的晶粒尺寸约为150微米，晶粒内的亚结构是典型的树枝状。Senkov通过固溶强化（SSS）模型计算的屈服强度与五种合金的实验屈服强度有一定的一致性。在我们的研究中，引入了结构熵的概念来优化模型。与原始模型的计算屈服强度相比，优化模型的变化趋势曲线与实验结果吻合较好。此外，优化的SSS模型具有一定的通用性，可以预测由W，Nb，Mo，Ta，Zr，Hf，Ti，V元素组成的单个BCC结构在其他耐火HEA系统中的机械性能。该结论为BCC结构耐火HEA系统化学成分的设计提供了理论依据。