Effect of microwave hybrid heating on high temperature dry sliding wear behavior of Al2O3 reinforced WC–Co HVOF coating

Abstract

Based on the application, wear is one of the most typical failure mechanisms, and this problem can be alleviated with some modifications. Oxide-based alloys are robust, wear-resistant, and erosion/corrosion-resistant. Thermal spray is considered to be one of the most effective methods for altering the outer layer of a base metal, as it safeguards against a variety of degradations and retains its properties despite exposure to high temperatures and severe working conditions. The thermal spray method often encounters issues like porosity and cavities, unmelted or partially melted particles, and residual stress, which result in limited surface resistance qualities. One of the most effective post-treatment methods that could be utilized to address these issues is microwave treatment. The coating powder WC12Co + Al₂O₃ were sprayed over the steel substrate using the high-velocity-oxy-fuel (HVOF) process trailed by microwave treatment. In addition to a heterogeneous microstructure characterized by fissures and cavities, the as-deposited coatings exhibited inadequate adhesion between splats. Microwave treatment enhances the erosion and friction resistance of coatings by promoting the formation of intermetallic phases and ensuring a uniform microstructure. The microwave-treated coating exhibits reduced breadth and more refined wear scarring due to the fatigue-spalling action. In contrast, coatings treated with microwaves have a more uniform structure, resulting in reduced surface roughness and porous. In contrast to the as-deposited coating, the mechanical and tribological properties of the WC12Co + Al₂O₃ coating were enhanced when subjected to microwave treatment.