Novel spraying composition, method of applying the same and article

Abstract

This application discloses a new powder composition which may be plasma sprayed onto the surface of an article to provide a protective coating therefor. The protective coating may be resistant to heat, wear, and corrosion. The coating may also provide a thermal or radiation barrier. In particular, the coating composition for arc plasma spraying consists of finely divided silicon carbide mixed with finely divided silicon. This coating composition is applied to a substrate by developing a plasma spray, feeding the coating composition to the plasma spray and directing the plasma spray at an exposed surface of the substrate so that the exposed substrate is coated with a coating which consists essentially of beta silicon carbide and silicon. The new article of manufacture disclosed in this application, is a substrate with a tightly adherent coating thereon consisting essentially of beta silicon carbide and silicon. The substrate may be any material, either metallic or non-metallic, to which the coating adheres. The coating may provide the substrate with wear resistant characteristics as, for example, if the substrate is to be used for machining metals or as a valve seat in an aluminum engine. The substrate, with the coating thereon, may be used to withstand severe temperatures as, for example, in rocket nozzles and other areas where a substrate would be subjected to extreme temperatures.