The effect of multi-element alloying on the structure and properties of laser cladding nickel-based coatings

In this paper, Ni60AA, Ni60AACu, Ni60AACuMo and Ni60AACuMoW composite coatings were prepared by laser cladding. The effects of alloying elements on the microstructure and properties of cladding coatings have been thoroughly investigated. The phases of the coatings are all composed of gamma-FCC + Cr-rich phases+ Ni-based FCC phase/(Ni3B + Ni2Si) eutectics. The Cr-rich precipitates in the coating decreased and the eutectics became finer after the addition of 2 wt% Cu. The Ni60AACu coating has the best wear and corrosion resistance at room temperature and 600 degrees C. Adding 2 wt% Mo to Ni60AACu coating promotes the segregation of Cr and Mo ele-ments, and the formation of coarse Cr-rich precipitates, all of which reduces the coating's wear and corrosion resistance. Adding 2 wt% W to Ni60AACuMo coating promotes the formation of the WC phase, which consumes C element in the gamma-phase and inhibits the precipitation of carbides rich in Cr and Mo. At 600 degrees C, Ni60AACuMoW outperforms Ni60AA and Ni60CuMo in terms of wear resistance.