The microstructures and tension properties of Fe₅₀Mn₂₀Cr₂₀Ni₁₀ medium entropy alloy (MEA) were investigated, which was produced by vacuum induction melting and subsequently was homogenized at 1200 °C for 6 h. Microstructure characterization shows the single-phase solid solution with face-centered cubic structure by means of transmission electron microscopy and scanning electron microscopy combined with energy disperse spectroscopy. Our Fe-MEA has an ultimate tensile strength of 550 ± 10 MPa and a high strain hardening exponent, n, of 0.41 as well as a higher ductility (60%) than those of CrMnFeCoNi alloy. The single-phase solid solution deforms plastically via dislocations and twins. Twin boundaries associated with deformation twinning impede dislocation motion, enhancing the strain hardening capacity. This article focuses on the insights into the concept of Fe-MEAs and provides a potential direction for the future development of high entropy alloys and MEAs.

研究了Fe ₅₀ Mn ₂₀ Cr ₂₀ Ni ₁₀中等熵合金（MEA）的组织和拉伸性能，该合金是通过真空感应熔化法制备的，然后在1200°C下均化6 h。显微组织表征通过透射电子显微镜和扫描电子显微镜结合能量分散光谱法显示了具有面心立方结构的单相固溶体。我们的Fe-MEA具有550±10 MPa的极限拉伸强度和高应变硬化指数n比CrMnFeCoNi合金具有0.41的韧性，以及更高的延展性（60％）。单相固溶体通过位错和孪晶发生塑性变形。与变形孪晶相关的孪晶边界阻碍了位错运动，增强了应变硬化能力。本文着重于对Fe-MEAs概念的见解，并为高熵合金和MEAs的未来发展提供了潜在的方向。