Adhesion Force Between Electroless Plated Ni-P/SiC Composite Coating and 45 Bearing Steel Substrate

Ni-P/SiC composite coating was fabricated on 45 steel substrate by electroless plating. The microstructure of the coating was studied using a metallographic microscope, scanning electron microscope (SEM ) , and an energy dispersive spectrometer (EDS). The relatioaship between the deposition amount of SiC particles in the coating and adding amount of SiC particles in the plating solution was analyzed. The adhesion force between the composite coating and the steel substrate was measured using a scratching tester. Results show that the composite coating had fine microstructure, and no inclusion or crack presented at the coating-substrate interface. At the same time, SiC particles were uniformly distributed in the composite coating, and the content of SiC in the composite coating increased with increasing concentration of SiC in the plating solution. The content of SiC in the coating reached a maximum value of 10. 6wt. % when the concentration of SiC in the plating solution was 6 g/L. Moreover, the adhesion force between the composite coating and steel substrate decreased initially with increasing concentration of SiC in the plating solution and then increased therewith. And the composite coating prepared from the plating solution containing 6 g/L SiC had the lowest adhesion force of 63 N.