INVESTIGATION OF THE FORMATION OF STRUCTURE AND WEAR-RESISTANT PROPERTIES OF WC–CO–CR COATINGS PRODUCED BY HVOF AND DETONATION SPRAYING

Abstract

The article presents a comparative analysis of WC–Co–Cr cermet coatings deposited by detonation spray (DS) and High Velocity Oxy-Fuel (HVOF) methods. The study included an analysis of the morphology of the initial powders, as well as the microstructure and phase composition of the coatings using Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The results show that the use of homogeneous, fully alloyed WC–Co–Cr powder ensures the formation of a dense, layered structure with a uniform distribution of the carbide phase within the metallic matrix. Detonation spraying produces a harder coating (average microhardness 1449 HV), whereas HVOF provides a coating with high density, uniform microstructure, and low friction coefficient (Kt = 0.143). The comparative analysis confirmed that the mechanical and tribological properties of the coatings strongly depend on the powder morphology and the spraying method. These findings allow for the determination of optimal processing conditions for WC–Co–Cr coatings, enhancing wear resistance and durability of machine parts, which is particularly relevant for operation under intensive friction and high load conditions.