Corrosion-resistant L12-strengthened high-entropy alloy with high strength and large ductility

Corrosion-resistant alloys with high strength and large ductility are desirable for applications in harsh envi-ronments where high structural load-carrying capacity is required. In this work, we designed an L12-strengthened high-entropy alloy (HEA) of composition (NiCo)77Cr13Al5Nb5 (at.%) that combines excellent mechanical prop-erties and good corrosion resistance. The formation of a thin passive film of non-stoichiometric compounds with an amorphous structure, characterized by an enrichment of Cr2O3 and Nb2O5, contributes to the superior localized corrosion resistance. The precipitation strengthening brought about by coherent L12 particles and the multi-stage plastic deformation dominated by stacking faults (SFs) provides ultrahigh strength and appreciable ductility, respectively.

Automated summary

In this study, an L12-strengthened high-entropy alloy (HEA) with composition (NiCo)77Cr13Al5Nb5 (at.%) was designed, which exhibits excellent mechanical properties and good corrosion resistance due to the formation of a thin passive film of non-stoichiometric compounds with an amorphous structure enriched in Cr2O3 and Nb2O5. The coherent L12 particles contribute to precipitation strengthening and the stacking faults (SFs) dominate the multi-stage plastic deformation, resulting in ultrahigh strength and appreciable ductility, respectively.