Effects of Powder Characteristics and High Velocity Flame Spray Processes on Hardmetal coatings: Part 2 — Cr3C2-WC-Based Coatings

Wear protection is a major application in thermal spray industry. Currently, Cr₃C₂- and WC-based hardmetal coatings with metallic are used for this including high-temperature performance. These materials are applied by high velocity flame spraying processes like HVOF and HVAF using liquid and gaseous fuel. However, these applications still face both economic and technical challenges, e.g. improving coating performance and increasing deposition efficiency.

This paper presents the latest results of a systematic study on the influence of Cr₃C₂/WC-based feedstock powder characteristics on the deposition efficiency and coating microstructures. A commercial Cr₃C₂-WC-M feedstock powder with 45 ma.% Cr₃C₂, 37 ma.% WC and 18 ma.% metallic binder was characterised and sprayed in two particle size distributions by kerosene-fuelled and ethene-fuelled HVOF, and HVAF. Coatings were heat-treated in argon at 800 °C. The coating microstructure, hardness, Young’s modulus and diffusion processes that occurred during heat treatment were related to the powder and spray processes.