A wear-resistant metastable CoCrNiCu high-entropy alloy with modulated surface and subsurface structures

Abstract Sliding friction-induced subsurface structures and severe surface oxidation can be the major causes influencing wear resistance of ductile metallic materials. Here, we demonstrated role in enhancing an equiatomic metastable CoCrNiCu high-entropy alloy (HEA). The HEA is composed a CoCrNi-rich face-centered cubic (FCC) dendrite phase Cu-rich FCC inter-dendrite phase. Copious nano-precipitates are formed distributed uniformly inside dendrites after tuning distribution composition two phases by thermal annealing. Although formation decreases hardness due to loss solid solution strengthening, these deformed form continuous nanolayers during dry sliding, leading self-organized nano-laminated microstructure extensive hardening subsurface. In addition, facilitate compacted glaze layers on worn surface, which also beneficial for reduction rate CoCrNiCu. current work extended other systems might provide guidelines designing fabricating wear-resistant alloys general.