Abstract A group of high entropy alloys (HEAs) in equal valence electron concentration (VEC), AlCoCr0.5FexNi2.5 (x = 0.5, 1.5, 2.5, 3.5), were melted and prepared. The microstructures and hardnesses were analyzed after homogenizing treatment. The results indicated that all of the equal-VEC HEAs consisted of FCC phase and BCC phase, their orientations obey Kurdjumov–Sachs relationship. This work also implied that the atomic size difference (Δr), like VEC, is an important parameter influencing the phase selection and worth considering in the HEA design. Fe is an FCC phase stabilizer for AlCoCr0.5FexNi2.5 HEAs and the ordered FCC phase (L12) gradually disappear with the Fe addition increased. The increasing FCC phase and the decreasing BCC phase resulted in the decreased hardness of HEAs.

中文翻译：

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等价电子浓度AlCoCr0.5FexNi2.5高熵合金的组织和硬度

摘要 熔化制备了一组等价电子浓度（VEC）的高熵合金（HEAs）AlCoCr0.5FexNi2.5（x = 0.5、1.5、2.5、3.5）。均化处理后进行显微组织和硬度分析。结果表明，所有相等的 VEC HEAs 均由 FCC 相和 BCC 相组成，它们的取向服从 Kurdjumov-Sachs 关系。这项工作还表明，与 VEC 一样，原子尺寸差异 (Δr) 是影响相选择的重要参数，值得在 HEA 设计中考虑。Fe 是 AlCoCr0.5FexNi2.5 HEAs 的 FCC 相稳定剂，随着 Fe 添加量的增加，有序的 FCC 相 (L12) 逐渐消失。增加的 FCC 相和减少的 BCC 相导致 HEAs 的硬度降低。