Plasma - Technology
Unlike thermal spraying using oxyacetylene flames, whether HVOF or arcs, which reach temperatures of between 3,000 and 4,000 °C, plasma spraying is employed when spray powder with a higher melting point is to be used. The plasma is created by means of a plasma torch in which a continually burning arc is fed argon, nitrogen, helium, hydrogen or a mixture thereof.
A wide range of uses for plasma spraying can be seen in the processing of ceramic spray powders. This includes
- pure aluminium oxides as an electrical isolation coating and protection against wear.
- chromium oxides as protection against wear with high corrosion resistance
- zirconium oxides as thermal insulator coatings
- aluminium oxides or titanium oxides as protection against wear
This process is also very effective for working with metal spray powder such as pure tungsten with a melting point of > 3.300 °C. These coatings are acid resistant and suitable for use with high temperatures.