The present work reports a systematic investigation on phase evolution, microstructure and microstructure–property relationship of two typical face-centered cubic (FCC) structured high-entropy alloys (HEAs), FeNiCoCr and FeNiCoCrMn, prepared via mechanical alloying (MA) followed by spark plasma sintering (SPS). Following 50 h of MA, the two HEAs consisted of a mixture of FCC and body-centered cubic phases. Following SPS, the bulk FeNiCoCr alloy showed a primary FCC phase with a small amount of Cr₂₃C₆ and Cr₂O₃ contaminants, while the bulk FeNiCoCrMn alloy was composed of a primary FCC phase with some (Cr,Mn)₂₃C₆ and MnCr₂O₄ contaminants. The average grain size of the primary FCC phase in the bulk FeNiCoCr alloy was ~ 416 nm, while that of the primary FCC phase in the bulk FeNiCoCrMn alloy was ~ 547 nm. The yield strength, compressive strength and strain-to-failure of the bulk FeNiCoCr alloy are 1525 MPa, 1987 MPa and 24.4%, respectively, whereas those of the bulk FeNiCoCrMn alloy are 1329 MPa, 1761 MPa and 21.9%, respectively. It suggests that the bulk FeNiCoCrMn exhibited lower strength and plasticity in comparison with the bulk FeNiCoCr alloy. Clearly, the smaller grain size of the primary FCC phase in the FeNiCoCr alloy is mainly responsible for the better mechanical performance.

本工作报告了对两种典型的面心立方（FCC）结构高熵合金（FeNiCoCr和FeNiCoCrMn）的相演化，微观结构和微观结构-性能关系的系统研究，这些合金是通过机械合金化（MA）然后通过火花制备的等离子烧结（SPS）。在MA 50小时后，两个HEA由FCC和以人体为中心的立方相的混合物组成。SPS后，FeNiCoCr块状合金表现出具有少量Cr ₂₃ C ₆和Cr ₂ O ₃杂质的FCC主相，而FeNiCoCrMn块状合金则具有一些（Cr，Mn）₂₃ C _6的FCC主相组成。和MnCr ₂ O ₄污染物。FeNiCoCrMn块状合金中FCC初相的平均晶粒尺寸约为416 nm，FeNiCoCrMn块状合金中FCC初相的平均晶粒尺寸约为547 nm。FeNiCoCr合金的屈服强度，抗压强度和断裂应变分别为1525 MPa，1987 MPa和24.4％，而FeNiCoCrMn合金的屈服强度，抗压强度和断裂应变分别为1329 MPa，1761 MPa和21.9％。这表明与FeNiCoCr合金相比，FeNiCoCrMn合金的强度和塑性较低。显然，FeNiCoCr合金中初级FCC相的晶粒尺寸较小，主要是因为其机械性能更好。