Microstructure and Properties of Ni-P-SiC Electroless Composite Plating Coating on AZ91D Magnesium Alloy Surface

Ni-P-SiC composite plating coating was prepared on the surface of AZ91D magnesium alloy by electroless composite plating. The microstructure and phase structure of the coating were analyzed using scanning electron microscopy and X-ray diffraction. The electrochemical test and wear resistance test were performed. The results indicate that the uniform and dense Ni-P-SiC composite plating coating was prepared with no obvious defect. The SiC particles were uniformly dispersed in the coating. The composite coating exhibited an amorphous structure with a high micro-hardness of 643 HV. The coating had a evident passivation region, that showed excellent corrosion resistance. The wear resistance of the coating was superior to that of the Ni-P plating coating obviously.