Heterogeneous banded precipitation of (CoCrNi)93Mo7 medium entropy alloys towards strength–ductility synergy utilizing compositional inhomogeneity

Compositional inhomogeneity of the Mo element in a (CoCrNi)93Mo7 alloy is utilized to obtain a heterogeneous structure with the banded precipitation, which improves the strength and ductility synchronously compared with the conventional structure with σ phase precipitates formed at grain boundaries. The interactions between dislocations and fine precipitates, twinning induced plasticity and inhomogeneous plastic deformation are beneficial to the high capability of work hardening and strength-ductility synergy. This work demonstrates the positive effect of compositional inhomogeneity to develop advanced high entropy alloys with heterogeneous structure via composition design and process optimization.