Enhanced corrosion resistance of CoCrFeMnNi high entropy alloy using heterogeneous structure design

High entropy alloys (HEAs) with heterogeneous grain structure exhibit an unprecedented combination of high strength and high ductility. Therefore, it is imperative to clarify corrosion behavior for various applications. In the present work, the corrosion behavior of harmonic structured (HS) CoCrFeMnNi HEAs with different shell fractions was investigated. The inhomogeneity of corrosion in the HS CoCrFeMnNi HEAs was revealed. The peculiar core-shell network structure is beneficial to the corrosion resistance compared with the conventional coarse-grained (CG) or ultrafine-grained (UFG) structure. The shell fraction of approximately 30% is the optimized design for corrosion resistance.