Formation of WC/12Co Coatings by High Velocity Oxygen-Fuel Spraying withHigh Wear Resistance and Lower Surface Roughness

摘要

The structural and mechanical properties, in terms of surfaceroughness, hardness and wear resistance, of WC/12wt%Cocoatings are investigated as a function of powder properties,such as powder size and WC grain size, as well as highvelocity oxygen-fuel (HVOF) spray conditions. It has beenfound that the WC/12wt%Co coatings with relativelysmoother surface, about 2 μm in average surface roughness(Ra), retaining high wear resistance can be formed byoptimizing the powder and spray parameters. Further, we havefound that powder size can control the surface roughness overa wide range; from about 2 to 7 μm (about ?5 μm) in Ra. Onthe other hand, Ra changed only about ?1 μm or more whenchanging spray conditions, such as barrel length and spraydistance.