What material is generally used as the cathode material of the plasma spray gun?

       In the past, tungsten electrodes (containing 1.5% ~ 2% thorium oxide) were commonly used, and in recent years, cerium tungsten (containing 2% ~ 3% cerium oxide) was used instead of thorium tungsten. When using cerium tungsten as the cathode, it has the following advantages:



    (1) When the current density is small, the arc starting current is extremely lower than that of thorium tungsten, and the stability of the plasma arc is good;

    (2) When using the same specification parameters, the burning loss of cerium tungsten is extremely small compared with thorium tungsten;

    (3) The radioactive dose produced by the cerium tungsten electrode is much smaller than that of the thorium tungsten electrode, which reduces the harm to the human body.

      The effect of direct cooling is good, but the structure is complicated. The effect of indirect cooling is poor, but the structure is simple, the cathode is adjusted and the replacement is convenient.