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Information × Registration Number 0223U001740, 0121U111822 , R & D reports Title Technology of combined laser and pulse-plasma application of wear-resistant coatings to strengthen the barrels of firearms. popup.stage_title Head Smyrnov Ihor V., Доктор технічних наук Registration Date 02-02-2023 Organization National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute" popup.description2 Two original processes of increasing the wear resistance of external and internal surfaces of firearms barrels by using the combined technology of laser surface hardening and ion plasma nitriding, as well as laser thermal cycling of plasma coatings have been developed. It is shown that laser pretreatment of inner cylindrical surface steel samples 40ХН2MA allows to obtain a nitride-hardened surface layer 3 mm wide and 0.2-0.4 mm deep with a surface hardness of 450-500 HV due to the formation of a highly dispersed structure with a high density of dislocations disoriented in space. Physico-mathematical models of electrical and gas supply of the discharge were built, according to which physical processes during ion nitriding were studied and the basic characteristics of the equipment were calculated. Proposals for the selection of gas discharge systems. Technological modes of pulsed ion-plasma nitriding of internal surfaces have been developed on the basis of an experimental vacuum unit which is equipped with a source of constant regulating voltage, a high-frequency generator and a pulse modulator. An experimental mockup was created to carry out research on the conditions of creating a stable and homogeneous plasma discharge in long tubes of small diameter. As a result of the research, it was found that ion-plasma nitriding of internal surfaces leads to the formation of diffusion coatings consisting of areas with different chemical and phase composition using a hollow perforated anode. The maximum concentration of nitrogen is observed in the areas opposite the holes in the anode, which are made at a certain distance at a certain angle, respectively, the same areas contain a solid phase of iron nitrides discretely arranged in a soft matrix of alpha iron. Testings in conditions of dry metal-to-metal friction showed that wear resistance of nitrided samples is 3-5 times higher than that of the original nonnitrided samples. Product Description popup.authors Bloshchytsyn Mykhailo S. Golovko Leonid F. Dubnyuk Viktor L. Kaglyak Oleksiy D. Kuzmichev Anatoly I. Lysak Volodymyr V. Maikut Serhii O. Romanenko Victor V. Smirnov Igor V. Tzybulsky Leonid Yu. Chornyi Andrii V. popup.nrat_date 2023-02-02 Close