Surface treatment of workpiece in sealed chamber by glow discharge - where ionisation plasma burner is used to reinforce ionised gas in chamber, e.g. for nitriding or carburising steel

摘要

In the chamber, the ionisation of the gas is reinforced by the additional emission of ions which are created externally; and the workpiece is pref. treated in the region of a falling current-voltage characteristic for the gas discharge. The workpiece pref. forms an electrically neutral element between a cathode and an anode, or may be used as the cathode or anode in the chamber. The treatment pref. occurs at an elevated temp., esp. in a thermally-insulated chamber and in vacuo; and the additional emission of externally created ions is pref. maintained by feeding gas into the chamber and igniting the gas, and by removing a corresp. amt. of gas from the chamber. Used for example, the nitriding or carburising of steels via a glow discharge in ionised gas.