Andreev A. Physical-technological fundamentals for vacuum-arc modification of surfaces

Object of research: the nitrided layers on iron and superhard coverings. The aim: working out of physical-technological bases of vacuum-arc hardening of surfaces which include plasma thermochemical processing and deposition of wearproof coatings in common technological process. Methods: metallography with use of optical microscopy, X-ray analysis, raster electronic microscopy, X-ray microanalysis, microdurometry, nanoindenting. Results: the new mechanism of iron nitriding is offered, according to which this process depends only on the atomic nitrogen concentration and on the substrate temperature, and presence of ions of nitrogen directly does not influence on nitriding process. It is shown, that nitriding takes place at bombardment not only by ions, but also by electrons, and that the speed of nitriding is identical in both cases. For the first time the superhard TіN coatings are created with use of ion implantation in the process of their deposition. Processes of deposition of superhard TіN coatings are developed at temperatures of a substrate 100…200°С. Multilayered coatings TіN-CrN with hardness to 60 GPa, in particular with ion implantation, are received. It is established, that these coatings keep superhigh hardness and phase structure after annealing in vacuum at 1000°С. For the first time possibility of deposition of superhard Tі-Sі-N coatings by vacuum-arc erosion of powder cathodes is shown. It is established, that cathode spots are localized mainly on TіSі eutectic, which forms on a surface of the cathode in the process of erosion. Features of erosion of powder cathodes, ways of decrease in quantity of macroparts on coatings Tі-Sі-N are investigated. The field of application: physics of a solid state, the physics of coatings, physics of superhard materials, nanophysics.