Abstract A series of NbC/FeCrNiCu high entropy alloy matrix composites (2.5, 5, 7.5 and 10 vol% of NbC) were prepared by vacuum induction melting. The microstructures and mechanical properties of the composites were investigated using X-ray electron diffraction, scanning electron microscopy, transmission electron microscopy, tensile and hardness tests. The results show that the FeCrNiCu high entropy alloy matrix composites are composed of FCC solid solution embedded with NbC particles. A coherent relationship was identified between the alloy matrix and reinforcement phase. The formation of NbC particles increases the hardness from 337.6 HV to 591.3 HV. Moreover, compared with the base alloy, the tensile yield strength, ultimate tensile strength and ductility of the new composite first increases and then decreases with the increase of NbC content. The tensile yield strength, ultimate tensile strength and ductility reaches maximum for the composites containing 5 vol% of NbC, which is 458.2 MPa, 691.6 MPa and 24.7%, respectively. The strengthening mechanisms of the composites are discussed and the contributions of dislocation strengthening, load bearing effect and Orowan mechanism are quantified.

中文翻译：

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NbC颗粒增强原位FeCrNiCu高熵合金基复合材料的显微组织和力学性能

摘要 采用真空感应熔炼方法制备了一系列NbC/FeCrNiCu 高熵合金基复合材料（NbC 体积分数为2.5、5、7.5 和10 vol%）。通过X射线电子衍射、扫描电子显微镜、透射电子显微镜、拉伸和硬度测试研究了复合材料的微观结构和力学性能。结果表明，FeCrNiCu高熵合金基复合材料是由嵌入NbC颗粒的FCC固溶体组成。确定了合金基体和增强相之间的相关关系。NbC 颗粒的形成使硬度从 337.6 HV 增加到 591.3 HV。此外，与基体合金相比，新型复合材料的拉伸屈服强度、极限拉伸强度和延展性随着NbC含量的增加先增加后减小。NbC 含量为 5% 的复合材料的拉伸屈服强度、极限拉伸强度和延展性达到最大值，分别为 458.2 MPa、691.6 MPa 和 24.7%。讨论了复合材料的强化机制，并量化了位错强化、承载效应和 Orowan 机制的贡献。