Nitriding in a cyclically switched glow discharge

Abstract

The paper shows the prospects of nitriding in a cyclically switched discharge, the classification of nitriding processes in a glow discharge according to the criteria of the characteristics of the power source is given. A comparison of the advantages and disadvantages of nitriding processes with constant and cyclically switched discharge is given.From a theoretical point of view, the process of nitriding in a cyclically switched glow discharge  is considered based on the concept of an energy model. In accordance with this model, tasks for further theoretical and experimental research are formulated. It is shown that the process of surface modification in a cyclically switched discharge opens up new possibilities associated with variants of the CSD itself, which is characterized by: frequency, period and pulse shape. The implementation of the process of adjusting the switching frequency, pitch - the ratio of the cycle period to the duration of the signal, and the shape of the signal itself opens up wide opportunities to significantly influence the results of surface treatment. The influence of the shape of the discharge power signal on the kinetics of the nitriding process and its results opens up wide opportunities for studying the process itself. The presence of surges at the beginning and at the end of the cycles can, in principle, significantly affect both the nature of the nitriding process itself and the structure and phase composition of the modified surface layer, since short-term and sufficiently powerful voltage surges should lead to intensive surface sputtering. The destruction of the monolayer of nitrides, which has just formed on the surface, will contribute to the increase of the depth of the nitrided layer due to the diffusion of nitrogen particles, as well as to a certain extent leveling off the blocking effect of the surface nitride layers.