APS (Air Plasma Sprayed) coatings are produced by heating and accelerating powders in a high-temperature plasma plume, which is projected onto the surface of the part.

The plasma plume is produced in a special torch. An electric arc is generated between the cathode and the anode whose energy is used to produce the dissociation and ionization of the gases that form the plasma. The constriction of the plasma arc due to the strong expansion of the gas causes an increase in the current density and therefore in the temperature. The plasma exits the nozzle at high speed and is seen as a very bright plume.

The powder is introduced into the plasma plume as it exits the torch. The powder particles are melted in the plasma plume and accelerated towards the part to be coated, where they cool, solidify and mechanically and metallurgically adhere to the substrate.

Advantages

• Wear protection
• Corrosion and oxidation protection
• Thermal insulation of surfaces
• Electrical conductivity or electrical resistivity
• Dimensional restoration of parts
• Realization of abradable coatings
• Adhesive coatings (bond-coat) for other coatings
• A cheaper method to improve the properties to a surface

Applications

Aerospace

• Components of engines
• Combustion chambers

Energy (Gas turbines)

• Combustion chambers
• Nozzles
• Injectors
• Burners
• Liner and Cap Liner
• Transition pieces
• Cooling tubes
• Sectors of stator rings

Materials

• Stainless steels (austenitic and martensitic)
• Nickel and Cobalt based super alloys
• Titanium alloys