Plasma spray coating

The plasma spray coating is a coating method based on generation of a stream of high temperature ionised plasma gas. The coating material is injected into the plasma gas stream, typically in a form of powder, mixed with an inert gas. The plasma gas stream with temperature of over 12000 K and speed of 400 – 800 m/s is the source of heat and velocity needed for melting and propelling of the coating material onto the parts surface. The coating material then solidifies on the parts surface, and creates a coherent coating layer.

Main advantages:

  • Very versatile coating method, that allows for coating with many different compounds, thus achieving different surface properties
  • High temperature of plasma gas jet enables to use high melting-point materials for coating and thus achieving of high temperature resistance of the coated surface
  • Increase of durability, hardness and wear resistance of the coated surface
  • Thermal and electrical insulation, improved thermal shock resistance of the coated surface
  • Provide better performance and decrease maintenance costs, which result in a longer service life.

Aluminum oxide (Al2O3)

Aluminum oxide is the most common oxide of aluminum with wide industrial usage. Coating with aluminum oxide is very wear-resistant, chemically inert and stable at medium temperatures, depending on the crystalline phase and the deposition temperature. Other advantages are elimination of arcing, very good non-stick properties of the coated surface, and the inert layer acts as a separator between graphite and metal parts, preventing carburizing.

Zirconium dioxide (ZrO2)

Zirconium dioxide is a white crystalline oxide of Zirconium. Zirconium oxide coatings are usually stabilized with other elements, like Yttrium (in form of Yttrium Oxide (Y203), to further enhance its properties.