Strengthening and toughening the FeNiCrMn medium entropy alloy by novel ultrafine precipitate networks

We have developed a Co-free equiatomic FeCrNiMn alloy with high yield strength and elongation. The novel networks composed of ultrafine precipitates were introduced into the cast FeCrNiMn alloy by annealing. In addition, the coarse dendrites formed during casting are dramatically reduced by annealing. The yield strength and elongation of newly-developed medium entropy alloy are 398 MPa and 60.2% at room temperature, which are superior to the performance of expensive FeCoNiCrMn high entropy alloys. The excellent mechanical properties benefit from the newly-formed networks composed of ultrafine precipitates and the sharp decrease of coarse dendrites during annealing.