process description plasma spray is perhaps the most flexible of all of the thermal spray processes as it can develop sufficient energy to melt any material. since it uses powder as the coating feedstock, the number of co......process description plasma spray is perhaps the most flexible of all of the thermal spray processes as it can develop sufficient energy to melt any material. since it uses powder as the coating feedstock, the number of coating materials that can be used in the plasma spray process is almost unlimited. a high frequency arc is ignited between an anode (nozzle) and a cathode (electrode). process gases (generally mixtures of argon, nitrogen, hydrogen and helium) flowing between them is ionized to become a plume of hot plasma gas with that exceed the surface of the sun of 6,600 c to 16,600 c (12,000 f to 30,000 f). when the coating material is injected into the gas plume, it is melted and propelled towards the target substrate. features of the atmospheric plasma spray process: - large choice of coating materials, including metals, alloys, ceramics, cermets, carbides and others. - coating systems are possible, using layers of different materials. - produces surfaces for a wide variety of applications, including resistance to many different types or wear and corrosion mechanisms, desirable thermal or electrical characteristics, and surface restoration and dimensional control. - excellent control of coating thickness and surface characteristics, such as porosity and hardness . - no heat affected zone or component distortion. - high deposition rate. - high bond of the coating to the substrate. - coating of complex geometries. - easy masking of areas that should not be coated. - process can be fully automated. - coating of internal geometries possible