Effect of carbide on wear mechanisms at 300 °C of composite coatings sprayed by HVOF

Abstract

Evaluation of the wear behavior of composite coatings based on Stellite 6 with additions of WC-Ni and Cr₃C₂, produced via high-velocity oxygen fuel (HVOF) spraying at an elevated temperature. Evaluation of the effects of these carbides on the wear mechanism and to determine their impact on the formation of protective tribolayers. Stellite 6, a cobalt-based alloy, is widely known for its resistance to wear and corrosion, and the incorporation of carbides such as WC-Ni and Cr₃C₂ further enhances these properties. Two types of composite coatings were developed: SW (Stellite 6 with WC-Ni) and SWC (Stellite 6 with WC-Ni and Cr₃C₂). Microstructural analysis revealed that the carbides were uniformly distributed in the Stellite 6 matrix, with higher hardness and improved wear performance compared to similar coatings without carbides. Wear tests were conducted at room temperature and 300 °C. The results indicate that both coatings exhibit low wear rates caused by different wear mechanisms when tested at elevated temperatures.