Plasma torch with long life electrodes

摘要

A plasma torch (10) for a plasma spraying system has anode and cathode (22) electrodes with active electrode sections which interact directly with the arc struck between the electrodes and which consist of a high melting metallic material. The active anode section (30) material and the active cathode section material has insignificant and significant contents, respectively, of additions in the form of dopants with low electron emission work function. Preferably, the active anode section (30) material has a dopant content of /}1.0 (preferably /}0.01, especially 0) wt.%, and the active electrode sections are powder metallurgically produced from tungsten and/or molybdenum powder containing up to 1 wt.% group VIII element (preferably nickel, palladium and/or platinum) as sintering activating material.