Investigation in electroless Ni–P–Cg(graphite)–SiC composite coating

Electroless nickel and electroless composite coating with graphite (Cg) and/or SiC particles were deposited by electroless plating. The micrograph of different coatings was conducted with scanning electron microscopy(SEM). X-ray diffraction(XRD) and differential scanning calorimetry (DSC) was used to analyse the microstructure and study the phase transition of the coatings during the heat treatment, respectively. Additionally, the mechanical and tribological properties were measured by microhardness tester, ring and disk machine, respectively. The effects of Cg and SiC on the structure and properties of the coatings are discussed. Finally, the worn surface of Ni–P–Cg–SiC is analysed by SEM and energy-dispersive analysis of X-ray (EDAX). The results demonstrated that Cg and SiC particles have little influence on the phase transition of the coating. Ni–P–Cg–SiC composite coatings showed a moderate microhardness between Ni–P–Cg and Ni–P–SiC, and had a low friction coefficient and good anti-wear.