Comparative Analysis on Reinforcement of Potential Additives in WOKA Cermet HVOF Coating Subjected to Slurry Erosion in Ash Conditions

Abstract

In this paper, an investigation was carried out to test the suitability of potential additive materials in WOKA 3533 (WC-10Co4Cr) cermet HVOF coating subjected to slurry erosion in ash conditions. The additives namely molybdenum carbide, yttrium oxide, and zirconium oxide were added in equal percentages (3 wt.%) in WOKA cermet powder. High-velocity oxy-fuel (HVOF) spraying was performed to develop the additive-based WOKA cermet coatings. The slurry erosion in ash conditions was tested using the pot tester. Microstructural and mechanical properties of traditional and additive-based WOKA cermet coatings were also tested in the present study; for example, microstructure, crystalline phases of as-sprayed coatings, and microhardness. Results present a comparison of surface erosion wear of different cermet coatings. It was found that the yttrium oxide was a suitable additive for the WOKA cermet coatings than the molybdenum carbide. However, zirconium oxide is unsuitable for WOKA cermet coatings in erosion wear applications.

Keywords

• slurry erosion
• hvof coating
• cermet
• slurry pump
• ash transportation