Improving ductility and strength of high-entropy alloy [formula omitted] via multi-directional forging and annealing.

A dual-phase high-entropy alloy Fe 50 Mn 30 Co 10 Cr 10 is treated via multi-directional forging (MDF) and subsequent annealing at 600°C–1000°C. Different microstructures with totally different grain sizes and phase ratios are obtained. The MDF increases yield strength and ultimate tensile strength at the expense of ductility. Via annealing the MDF-processed alloy at 1000°C, the full recrystallized sample yields a excellent combination of high strength and good ductility due to the grain boundary strengthening, transformation-induced plasticity and twinning-induced plasticity. The yield strength, ultimate tensile strength and elongation at failure are 16.2%, 14.2% and 35.3% than those of the as-cast sample. The postmortem characterizations of this annealed sample show strong 〈 111 〉 texture in the austenite phase along the loading direction and intense martensite transformation with the gradually disappearance of the annealing twins. [ABSTRACT FROM AUTHOR]