4. Plasma-assisted treatment or ion nitriding and nitrocarburizing

4.1 Principle

When a potential difference is imposed between an anode and a cathode in a gaseous atmosphere at low pressure, ionizing electron-molecule collisions occur and, above a certain potential (disruptive potential), a glow discharge regime is established with the production of ionized species in the vicinity of the cathode. The conditions under which this discharge occurs depend, among other factors, on the nature of the gases and the pressure in the enclosure. For ionic heat treatments, the so-called "abnormal discharge" zone is used (figure 31 ).