The Plasma Spray Process is the spraying of hot or heat dissolved material onto a surface to give a coating. The material in the form of powder is added into a very high-temperature plasma flame. It is immediately heated and stimulates to a high speed.

Thick Coatings which resist wear by fibers and cotton and also resist corrosion at high temperatures. Plasma Coating can be used, in various conditions including most acids and bases. High-quality plasma spray coating for use in the compressor section of jet engines.

How does Plasma Coating work?

Plasma is the term used to describe a gas that has been heated to such high temperatures that it ionizes and becomes electrically charged. The plasma spray gun achieves this by utilising the combination of a copper anode and tungsten cathode inside the gun, around and through which a gas (usually either argon, nitrogen, hydrogen or helium) flows. This causes the gas to become plasma where it is then forced out through a constricting nozzle where it is mixed with the coating substance in powder form. The powder then becomes molten and is fired out of the gun towards the substrate where it then cools and forms a coating.

Top Uses Of Plasma coating

When carried out correctly the plasma spray coating process is known as a ‘cold process’, as even though the plasma stream itself is very hot, the actual temperature of the substrate material that is to be coated can be kept relatively cool. This means that damage, metallurgical changes and distortion to the substrate material can be avoided and so more delicate substrate materials can be successfully coated using this process. However the extreme heat of the plasma also means that materials with very high meting points, such as refractory metals e.g. tungsten and ceramics e.g. zirconia, can used as coating materials.

Advantages of Plasma coating

  • Wide variety of materials that can both be coated and be used to form coatings.
  • Higher quality coatings can be achieved compared to other types of thermal spray processes.
  • A broad range of powder particle sizes can be used, typically between 5-100µm.
  • Well known process that is widely available and well understood.