Wear and corrosion resistance improvement of (CoCrNi)72−xB18Si10Nbx coatings obtained by laser cladding: Role of Nb concentration

(CoCrNi)72−xB18Si10Nbx (x = 0, 2, 4, 6, 8) high-entropy alloy composite coatings were prepared by laser cladding. The (CoCrNi)72B18Si10 coating was composed of a dual-phase FCC structure with one phase rich with Co, Ni, and Si, and the other willow-like ceramic phase rich with Cr and B. The addition of Nb led to the formation of an FCC ceramic phase, i.e., the G-phase, which changed the morphology and properties of the coatings. Due to solid solution strengthening and second phase strengthening, the mechanical properties of the coatings were greatly improved, which enhanced the wear resistance. The corrosion resistance was also enhanced due to the improvement of passive ability with the addition of Nb.