METHOD OF FORMING SELF-INCANDESCENT HOLLOW CATHODE FROM TITANIUM NITRIDE FOR NITROGEN PLASMA GENERATING SYSTEM Russian patent published in 2014 - IPC H05H1/24 

FIELD: physics.

SUBSTANCE: invention relates to plasma engineering and can be used for strengthening treatment of components made of steel and nonferrous metal alloys by plasma nitriding. The disclosed method involves mounting a hollow titanium cathode in a discharge system having an anode, constantly pumping a working gas - nitrogen - through the hollow cathode, applying voltage between the anode and the hollow cathode and igniting glow discharge, the current of which is set such that in a few minutes, temperature of the hollow cathode increases to temperature close to the melting point of titanium (1668±4°C), forming a titanium nitride layer on the surface of the hollow cathode and switching discharge to a low-voltage arc mode with a thermionic cathode. The cathode is then hardened in the arc mode, for which the arc discharge current is increased while simultaneously reducing combustion voltage thereof, keeping temperature of the hollow cathode close to the melting point of titanium and maintaining discharge in such a mode for 40 minutes.

EFFECT: enabling measurement of discharge parameters in a wider range limited by reaching the melting point of titanium nitride, and multifold increase in discharge current.

6 dwg