Heterogeneous Microstructure and Tensile Properties of Fe₅₀Mn₃₀Co₁₀Cr₁₀ Metastable High-Entropy Alloy

Face-centered cubic (FCC)-structured high-entropy alloys (HEAs) are facing a major challenge due to a trade-off between strength and ductility. In this paper, we systematically investigated the microstructural evolution and tensile properties of metastable dual-phase (DP) FeMnCoCr HEAs via cold rolling and partial recrystallized annealing, which resulted in a heterogeneous microstructure, and by inducing strengthening and strain-hardening through heterogeneous deformation-induced (HDI) strategies. The results show that the alloy was annealed at 600 °C for 10 min, exhibiting a good combination of strength and ductility. A higher alloy strength was obtained via HDI strengthening, while FCC → HCP phase transformation, deformation twins, and HDI strain-hardening contributed to the excellent ductility. The results provide a viable method for the design of subsequent alloys.