Novel B2-strengthening Ni–Co–Cr–Al medium-entropy alloys with prominent mechanical performance

High-/medium-entropy alloys (H/MEAs) with multiple principal elements and promising performance have opened up an unprecedented multi-dimensional compositional space for exploring novel materials. Here, we report a novel B2-strengthening Ni–Co–Cr–Al medium-entropy alloy system with a better combination of strength and ductility. Through simple thermomechanical processing, gigapascal yield strength (∼1 GPa) and ultimate strength (∼1.5 GPa) combined with excellent uniform elongation (∼22%) were achieved. This excellent strength-ductility synergy resulted from the partial recrystallization combined with considerable fine B2 precipitates, and annealing twins in this dual-phase Al13 MEA. This work further broadens material design and optimization space and offers a paradigm for developing heterogeneous microstructures in dual-phase MEAs through alloying and regulating recrystallization and precipitation behaviors.