Deposition of Silicon Carbide based Coatings using High Velocity Oxy-Fuel Spraying

Deposition of Silicon Carbide based Coatings using High Velocity Oxy-Fuel Spraying Riley MA, Tabecki AK, Zhang F Development of a new SiC-based powder has enabled the deposition of dense silicon carbide coatings using thermal spraying techniques for the first time. Previously it has not been possible to deposit good quality coatings of SiC using thermal spraying as SiC decomposes at 2700°C. The lower flame temperature of the HVOF process, compared to plasma spraying, has enabled deposition of dense SiC based coatings, which have the potential to replace other wear resistant coatings such as alumina and WC and Cr3C2 based cermets. Additionally, the low density material makes it attractive from a weight saving perspective, whilst also being a cost effective alternative for a wide range of industrial applications This paper discusses the deposition of SiC based coatings, using gas and liquid fuelled high velocity oxy-fuel spraying techniques. The properties of the deposited coatings in terms of microstructure, hardness, adhesion/cohesion strength, wear and erosion resistance have been determined, and the performance compared with alumina and WC-CoCr HVOF coatings. Based on the findings of this work, recommendations are made on potential applications of SiC based coatings.