Effects of yttrium-stabilized zirconia (different yttrium content) doping on the structure, corrosion resistance and wear resistance of Ni-P electroless coating

In this paper, yttrium-stabilized zirconia (3YSZ, 5YSZ, and 8YSZ) with different Y element contents were co-deposited with Ni-P coatings by electroless plating. Zirconium dioxide (ZrO2, without Y element) nanoparticles were introduced as a comparison. YSZ with different Y contents was doped into the Ni-P coating, and its effect on the microstructure, phase structure, element valence, corrosion resistance and wear resistance of the coating was studied. The results show that the metal oxidation states (such as NiO and -POx) on the surface of the coating are enriched with the increase of Y element in YSZ. Ni-P coating is amorphous, while the Ni-P-YSZ coating exhibits obvious crystalline diffraction and its intensity is proportional to the Y content. The corrosion resistance of the coatings also showed a similar trend. Among them, the Ni-P-8YSZ coating has the best performance, and its corrosion rate is about 40% of the Ni-P coating. In addition, friction experiments show that the wear rate of the composite coating is about 60–70% of the Ni-P coating, indicating that the doping of YSZ also affects the wear resistance of the coating.