Effect of CeO2 particles on the low phosphorus electroless Ni layer

摘要

In this paper, the influence of nano-CeO and micro-CeO with different amounts were discussed after they were added into low phosphorus content Ni-P composite coating. The microstructure and crystal structure of the coating were observed by scanning electron microscope (SEM) and X-ray diffraction analysis (XRD) respectively. The results showed that whether nano-CeO or micro-CeO, both refined the grain, increased the specific surface area, however the micro-CeO was more obvious. As to XRD, the peak gradually became gentle, the coating turned into amorphous state caused by CeO absorbed in the grain boundary and crystal defects. All the results indicated CeO mixed with the coating very well. Finally, the corrosion resistance of the coating was tested with the method of Electrochemical impedance (EIS) and linear polarization. When the dosage was 5g/L, the corrosion was the best leading by the grain refinement. However, lower corrosion resistance was got when added more CeO which may affected by the catalytic property.