Metallographical Aspects of the Application of Special Paint Layers for the Protection of Machine Part Sections against the Effect of lonitriding

Abstract

The paper presents aspects concerning the appreciation of the protection through special paints based on copper powders used against plasma nitriding. First of all the choice of copper is motivated as an important metallic component of protecting paints, with the characteristics that the copper presents in the context of the physical and chemical phenomena (from the cathode and from gas volume) specific for the ionic nitriding process. The paper contains comparatively some characteristics (the duration of drying on the coat, the compatibility of the components, the capacity of extension and of avoiding the leakage, the power of covering, the capacity of joining, and the emitting of gases, the resistance in friction before and after the ionic nitriding, the way of obtaining the copper powder and its quality, the capacity of removing after ionic nitriding etc.) of the mixtures, for the protection against ionic nitriding. Following the researches on making more efficient technologies of local protection of metal pieces on certain areas with isolated layers against plasma nitride, the authors realized 2 different kinds of special original paints noted V-1 and V-2 used for this purpose. These paints are made having a basis of copper powder combined with magnesium oxide and polystiren dissolved in carbon chloride.