In plasma spraying process, the material to be deposited (feedstock) — typically as a powder, sometimes as a liquid, suspension or wire — is introduced into the plasma jet, emanating from a plasma torch. In the jet, where the temperature is about of 10,000 K, the material is melted and propelled towards component’s surface. There, the molten droplets flatten, rapidly solidify and form a deposit. Commonly, the deposits remain adherent to the substrate as coatings.
Powder & wire flame spray
With the combustion wire spray process, the wire spray material is melted in a gaseous oxygen-fuel flame. The wire is fed continually into the fuel gas-oxygen flame, where it is melted and atomized by the addition of compressed air that also directs the melted onto the substrate.