Low temperature gas-phase technology cladding powdered silicon carbide

Abstract

A technology for applying a metal coating to the surface of powdered silicon carbide has been developed. For this purpose, a film of copper phosphide is initially applied to the surface of the powder. The process consists in wetting the powdered carbide with a solution of copper sulfate and subsequent treatment with gaseous phosphine. The resulting film of metal-like copper phosphide has sufficient electrical conductivity, and is also a catalyst for the process of chemical nickel plating. This makes it possible to use chemical or electroplating methods for plating the surface of powders with the necessary metal. Testing this technology in the laboratory allowed obtaining a nickel coating that has the necessary adhesion to silicon carbide particles.All samples of powders at various stages of the process were examined using a scanning electron microscope ISM-6490-LV (JEOL, Japan), which allows to obtain electronic images (photos) of individual areas (spectra) of the surface at specified magnifications and chemical composition. The results of the scanning electron microscope study showed that the nickel coating contains 7 % phosphorus and covers about 90 % of the powder surface, and the estimated coating thickness is 0.8–1.0 microns. This makes it possible to use such silicon carbide powders in the preparation of composite products or coatings. If necessary, the degree of closure of the powder surface can be increased by re-performing the operation specified in this article. The article is intended for scientists and researchers, who are also interested in the problems of obtaining composite coatings.