Enhanced strength-ductility synergy in ferrous medium-entropy alloys via single-step hot rolling

The present study investigated the microstructure and mechanical properties of as-hot-rolled Fe 64 (CoCrNi) 36 (at.%) ferrous medium-entropy alloys (Fe-MEAs), demonstrating a remarkable 142 % enhancement in yield strength (YS) and a superior uniform elongation of 43.0 %, in comparison to the cold-rolled and annealed ones. The improvement of YS is attributed to dislocation strengthening, grain boundary strengthening, and hot rolling-induced defects such as stacking faults and Lomer-Cottrell (L-C) locks. Due to the enhanced yield stress, the pronounced transformation-induced plasticity (TRIP) effect supported the sustained uniform plastic deformation . These findings underscore hot rolling as an effective and straightforward strategy to reinforce Fe-MEAs.