Substrate surface processing in gas vacuum arc discharge

Abstract

Problem. Preparation of the surface before the deposition of vacuum arc coatings is of great importance, as it affects not only the adhesive properties of the obtained coatings, but also the physical and mechanical properties of the substrate surface layer. The processes of ions interaction with the substrate surface during its ionic cleaning, before the deposition of coatings, have been relatively little studied and are almost not described in the literature. Goal. In this work, some of their features are considered in relation to the surface preparation of materials before the deposition of vacuum arc coatings. Methodology. The nature of the plasma interaction with the substrate material is determined by the ions energy and their flow density, other things being equal. The energy of the ions treating the substrate consists of their initial energy and the energy acquired in the Debye layer adjacent to the substrate when a negative potential is applied to it. The value of the potential at which the processes of condensation or sputtering are balanced is determined mainly by the nature of the vaporized material. When the value of the substrate potential increases, the deposited particles and its material are sputtered. At the same time, atoms on the substrate that are weakly connected to it, various impurities are removed, substrate temperature increases, especially in its surface layers. Results. The work investigates the influence of various metals and gases used to clean the surface of substrates made of cubic boron nitride PcBN and steels on the surface morphology. It was established that the use of gases (argon, nitrogen) for cleaning the surface of dielectric materials, in particular PcBN, showed the best results, which subsequently leads to an increase in the adhesion of the vacuum arc coating to the substrate. Practical value. The obtained results of investigation are of great practical importance. They can be used for the increasing of tool life and productivity of mechanical engineering.