Strengthening of Fe50Mn25Ni10Cr15 Medium-Entropy Alloys by Mo Addition for Cryogenic Applications

The effect of Mo addition of Fe50Mn25Ni10Cr15 medium-entropy alloy (MEA) on its cryogenic mechanical properties is investigated. It is found that the optimized (Fe50Mn25Ni10Cr15)(99.5)Mo-0.5 MEA exposes the yield strength, tensile strength, and ductility of 690 MPa, 1148 MPa, and 63% at 77 K, respectively. Especially, the yield strength increases by 29% after Mo addition. Herein, the solid-solution strengthening, twinning-induced plasticity, and transformation-induced plasticity are beneficial to reveal the high work hardening capability and good strength-ductility synergy at 77 K. This research can offer guidance for the design of low-cost and high-performance MEAs for cryogenic applications.