Study of the Splat-Substrate Interface for a NiCr Coating Plasma Sprayed on to Polished Aluminum and Stainless Steel Substrates

A study of plasma-sprayed NiCr splats shows that the morphology and characteristics of the splat-substrate interface depends on the substrate material. Splats on stainless steel tend to be regular and disc-shaped and localized melting of the substrate and intermixing and diffusion were observed at the interface. Splats on aluminum, on the other hand, were slightly more irregular and the contact at the splat-substrate interface was found to be porous and poor. For both types of splats, several oxide phases were observed. Their formation and the formation of the splats are discussed, although further study is required to fully identify the origins of the differences observed.