Plasma torch head for interior coatings and method of manufacturing the torch head

Abstract

A plasma torch head, for interior coatings of rotationally symmetrical, asymmetrical, or freeform surfaces in concave or convex-shaped cavities with a distance between the surfaces to be coated greater than 40 mm using a plasma spraying process, includes a cathode whose tip has a surface roughness of less than Ra 0.2 μm and grooves running in the axial direction of the cathode, which is secured the cathode holder Gas tightness with respect to the plasma gas is ensured by high-temperature resistant O-rings, one O-ring preventing gas leakage between the cathode holder and insulation ring, and another preventing gas leakage between the insulation ring and anode. In the cathode holder, the outflow velocity of the plasma gas in holes above the center of the cathode is lower than below the center. A plasma torch head reduces voltage fluctuations over the entire operational life of the torch head and extends its service life.

Dependencies are inferred from the claim text.