Effect of CeO2 particles on the medium phosphorus electroless Ni layer

Add CeO₂ in medium phosphorus content Ni-P composite coating has been attracted attention in recent years. So, we add different amounts and different size of CeO₂ in the nickel plating solution, then the morphology and crystal structure of the coating are characterize by scanning electron microscope (SEM) and X-ray diffraction analysis (XRD) respectively. As a result, the content of CeO₂ in the coating increases with the rise of the CeO₂ concentration, moreover the grain of the Ni coating turns to amorphous state and the grain got refined. Finally, the corrosion resistance of the coating was tested with the method of Electrochemical impedance (EIS) and linear polarization. Both methods get same result. The corrosion resistance of the coating enhances greatly after added CeO₂ in the plating solution. Different diameter of CeO₂ got different corrosion resistance, however mirco-CeO₂ got better performance which may due to micro-CeO₂ could refine the grain of the coating more efficient.