Autocatalytic Ni-P and Ni-B Deposition on SiC Ceramic Particles

Ceramic particles like SiC have attracted great attention because of their usability as reinforcement for composite materials. Autocatalytic (electroless) nickel deposition is a unique process for the enhancement of the surface properties of ceramic particles. In this study, deposition of nickel phosphorus (Ni-P) and nickel boron (Ni-B) layer on SiC particles via autocatalytic plating in hypophosphite and borohydride baths was investigated. SiC powders were sensitized and activated respectively in order to ensure catalytic properties. Electroless nickel coating was carried from two different nickel ion sources (nickel chloride, nickel sulphate) following the pre-treatments of particle surfaces. Coated powders morphologies were characterized by transition electron microscope (SEM). X-ray diffraction and energy dispersive spectroscopy (EDS) analysis were used to investigate the chemical analysis of coating layers. The results showed that a better uniformity and bonding were obtained for Ni-P coatings with the Ni source of NiSO₄.6H2+O as compared to NiCl₂.6H2+O. For Ni-B coatings, the Ni2+ source of NiC₁₂.6H₂O has provided better quality and continuous coating layer on SiC surfaces.