What is supersonic plasma spraying and how is it different from ordinary plasma spraying?

       Supersonic plasma spraying refers to the use of specially designed spray guns and nozzles, one or more times you supply a higher pressure, large flow of working gas, one or more stages of nozzles elongate the arc, so that the arc is strongly compressed. Thus, a supersonic plasma jet with a very high energy density is obtained. The process of using this supersonic plasma jet to heat and accelerate harmonious materials to obtain high-quality coatings is called supersonic plasma spraying.



    Differences from plasma spraying:

    (1) The working gas pressure is high and the flow rate is large. The pressure is greater than 980KPa, the flow rate is 4m3/h~25m3/h;

    (2) The working voltage is high. Voltage 120V~400V;

    (3) Jet length. It is about 15mm~20mm longer than ordinary plasma.

    In the mid-1990s, American TAFA Company introduced to the market the "PlazJet", a supersonic plasma spraying system with a high power of 270kW and a large gas flow (21m3/h) that can meet the needs of industrial production.

     Compared with ordinary plasma spraying, supersonic plasma spraying has the following characteristics:”

    (1) The energy is more concentrated;

    (2) The jet reaches supersonic speed;

    (3) The powder heating time is shortened and the oxidation is reduced;

    (4) The gas and electrical parameters can be adjusted, expanding the spraying range;

    (5) High-performance ceramic coatings can be prepared.