Abstract In this study, a novel cobalt-free Fe40Mn20Cr20Ni20 (at.%) medium-entropy alloy (MEA) with low cost is purposively designed. The partially recrystallized microstructure was introduced into the single-phase FeMnCrNi MEA via thermo-mechanical processing. Surprisingly, the present MEA displays ultrahigh yield and ultimate tensile strengths of 1.2 and 1.34 GPa, respectively, and large ductility with a uniform elongation of 22% at 77 K. This is mainly due to the accumulation and entanglement of a large number of dislocations and the activation of deformation twins at 77 K.

中文翻译：

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一种在低温下具有优异屈服强度和延展性的新型无钴 FeMnCrNi 中熵合金

摘要 在这项研究中，有目的地设计了一种低成本的新型无钴 Fe40Mn20Cr20Ni20 (at.%) 中熵合金 (MEA)。通过热机械加工将部分再结晶的显微组织引入单相 FeMnCrNi MEA 中。令人惊讶的是，目前的 MEA 分别显示出 1.2 和 1.34 GPa 的超高屈服强度和极限拉伸强度，以及在 77 K 下具有 22% 的均匀伸长率的大延展性。这主要是由于大量位错和变形孪晶在 77 K 时的激活。