Mechanical Properties and Tensile Fracture Study of Cast (CoCrNi)<sub>100</sub><sub>−</sub><sub>n</sub>Y<sub>n</sub> (n = 1, 2, 3, 4) High Entropy Alloys

本研究围绕铸态(CoCrNi)100−nYn (n = 1, 2, 3, 4, at %)高熵合金展开，着重探究钇(Y)含量对其力学性能及拉伸断口形貌的影响规律。研究结果显示，Y-1和Y-2的应力极限相等，不过Y-1的断裂伸长率更优；Y-3和Y-4的屈服强度相对较高，但塑性近乎消失。借助扫描电子显微镜(SEM)对拉伸断口进行分析，揭示了断口微观特征与宏观力学性能之间的内在关联，为高熵合金成分优化和性能提升提供了关键数据支持与理论依据。The present study centers on cast (CoCrNi)100−nYn (n = 1, 2, 3, 4, at %) high entropy alloys, focusing on the influence law of yttrium (Y) content on their mechanical properties and tensile fracture morphology. The results show that the stress limits of Y-1 and Y-2 are equal, but the elongation at break of Y-1 is better; the yield strengths of Y-3 and Y-4 are relatively high, but the plasticity nearly disappears. The analysis of the tensile fracture with the aid of scanning electron microscope (SEM) reveals the intrinsic correlation between the fracture microscopic characteristics and the macroscopic mechanical properties, which provides key data support and theoretical basis for the optimization of the composition and performance enhancement of the high entropy alloys.