Corrosion Behavior of WC-Ni Coatings Deposited by Different Thermal Spraying Methods

Abstract

This study compares the properties of WC-Ni coatings manufactured from fine powder particles using high-velocity oxygen fuel (HVOF) and high-velocity air fuel (HVAF) spraying processes. The results indicated that the decarburization of carbide phase is influenced by the spraying equipment. It was found out that the deposition velocity is an important factor influencing the bonding between splats and furthermore the coating density. The WC-Ni coating sprayed with the supersonic M3 HVAF spraying gun revealed the lowest degree of porosity and degree of decarburization, achieving the best properties in terms of electrochemical corrosion resistance when compared to the HVOF sprayed WC- Ni coating.