Corrosion and Wear Resistance of HVOF-Sprayed Ni-Cr-Co Multi-principal Element Alloy Coating on Copper Plate.

The development of protective coatings on copper alloy surfaces represents a critical research direction to enable the widespread industrial application of copper alloys. To improve the corrosion resistance and wear resistance of the copper alloy plates, a Ni-Cr-Co-based multi-principal element alloy coating was prepared via high-velocity oxygen fuel (HVOF). Then, the microstructure, corrosion resistance, and wear resistance of the Ni-Cr-Co coating and the electroplated NiCo coating were analyzed comparatively. The research results show that the phases of the Ni-Cr-Co coating contained face-centered cubic (FCC) solid solution, CrB and M23C6. The NiCo coating exhibited a single-phase FCC solid solution structure. Compared to the NiCo coating, the corrosion current density of the Ni-Cr-Co coating was reduced by 92.1% in NaF solution. A highly protective passive film was formed on the Ni-Cr-Co coating, and its low ΣCSL grain boundary proportion reached as high as 25.7%. Therefore, the Ni-Cr-Co coatings demonstrated superior corrosion resistance. The scratch wear coefficient of the Ni-Cr-Co coating was only 51.9% of that of the NiCo coating, due to the synergistic strengthening of the matrix and hard second phase. This research offers technical support and a theoretical basis foundation for the development of coatings on copper alloys with excellent corrosion resistance and wear resistance. [ABSTRACT FROM AUTHOR]