Synthesis of a duplex Ni-P-YSZ/Ni-P nanocomposite coating and investigation of its performance

In this study, a duplex NiP with yttria-fully stabilised zirconia (YSZ) nanoparticle composite coating was prepared by electroless deposition on a carbon steel substrate. The characteristics of the coatings were evaluated using scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The electrochemical and corrosion behaviour of the coating in a 3.5 wt.% NaCl solution was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). In addition, the effects of the YSZ nanoparticle concentration on the properties of the coatings were also discussed. The results show that the structures of the as-deposited duplex Ni-P-YSZ/Ni-P coating are amorphous, and it changes to a crystalline state after heat treatment. The surface roughness and morphology of the coating are affected by the addition of YSZ nanoparticles. The duplex coating exhibits both good microhardness and wear resistance as well as excellent corrosion resistance because of its special duplex structure.