Evaluation of Microstructure Characteristic of Stellite6 - WC/12% Co Composite Coatings Produced by HVOF Process on Carbon Steel

In this study, high-velocity oxygen-fuel (HVOF) process was applied to produce Stellite WC composite coatings on the surface of carbon steel samples. For this purpose, various amounts of WC powder 0%, 10%, 20% and 30% were mixed with Stellite6. The structural and mechanical behavior of the coatings were evaluated using Xray diffractometry, scanning electron microscopy, microhardness and roughness test. The results showed that the micro structure of the coatings were composed of a cobalt and chromium solid solution dendritic structure with the interdenderitic phases of cobalt enriched phase, carbides and WC particle. The XRD evaluations indicated that the coatings included Co-rich phase, CoCx , Co3W3C, Co6W6C as well as Cr23C6 and Cr7C3 carbides. Also, It was found that the hardness was increased, the adhesion was improved and the porosity was decreased by increasing the tungsten carbide as reinforcement.