HVOF cermet coatings to improve sliding wear resistance in engineering systems

Abstract

High-Velocity Oxy-Fuel (HVOF) cermet coatings are widely employed in sliding conditions, due to their optimized microstructure, composed of a carbide phase embedded into a ductile metal matrix. In the present short review, the characteristics and mechanical properties of HVOF cermet coatings are considered, and the dry sliding behaviour of the main types of coatings is analysed at room and high temperature. The role of microstructural parameters, including defects, surface roughness and the nature of the counterface is discussed. The review also considers a specific application, namely HVOF coatings for discs in brake applications. This application is gaining in importance, since it reduces the wear of the braking components and thus the emission of airborne particulate matter.