Видання зареєстровані авторами шляхом самоархівування
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Item Effect of Bilayer Thickness and Bias Potential on the Structure and Properties of (TiZr/Nb)N Multilayer Coatings as a Result(MDPI, 2022) Rakhadilov, B.; Погребняк, Олександр Дмитрович; Pohrebniak, Oleksandr Dmytrovych; Sagdoldina, Z.; Buitkenov, D.; Beresnev, V.; Mukhamedova, A.This work is devoted to the study of the formation of nanostructured multilayer coatings (TiZr/Nb)N on the surface of an AISI 321 steel substrate depending on the deposition parameters of the Arc-PVD method. The results of the X-ray diffraction analysis showed the formation of solid solution (TiNb)N and ZrN in the multilayer coatings with an FCC structure, "-NbN with a hexagonal structure, as well as with a small volume fraction of the "-Ti2N and -Nb2N phase. On the basis of phase composition data, it is possible to assume that an increase in the number of bilayers leads to a decrease in the nitrogen concentration in the bilayers and, consequently, to a decrease in the volume fraction of "-NbN and -Nb2N nitrides. In all investigated systems obtained at 100 V and 200 V bias potentials, "-NbN is the main phase. The study of the element distribution over the thickness of the (TiZr/Nb)N coating confirms the results of the X-ray diffraction analysis. The use of the structure model in the form of alternating layers allows for significantly improving the adhesion characteristics of the protective coating, as well as ensuring their high hardness. Based on the experimental results, it is possible to analyze changes in the mechanical and tribological properties of multilayer coatings depending on the number of applied bilayers. The results of the study of the elastic modulus and hardness of multilayer coatings (TiZrNb)N with different numbers of bilayers showed that a large number of bilayers (small thickness of each individual layer) shows the lowest value of hardness. It is assumed that as the bilayer thickness decreases, the coating characteristics are closer to the monolayer alloy than to the multilayer structure.Item Composition, Structure, and Properties of Ti, Al, Cr, N, C Multilayer Coatings on AISI W1-7 Alloyed Tool Steel(MDPI, 2022) Loskutova, T.; Hatala, M.; Pogrebova, I.; Nikitina, N.; Bobina, M.; Radchenko, S.; Харченко, Надія Анатоліївна; Харченко, Надежда Анатольевна; Kharchenko, Nadiia Anatoliivna; Kotlyar, S.; Павленко, Іван Володимирович; Павленко, Иван Владимирович; Pavlenko, Ivan Volodymyrovych; Іванов, Віталій Олександрович; Иванов, Виталий Александрович; Ivanov, Vitalii OleksandrovychNew methods of diffusion metallization of AISI W1-7 steel have been developed. The paper proposes a comparative analysis of the properties and characteristics of AISI W1-7 steel after three methods of chemical heat treatment: diffusion nitriding, nitrogen titration by physical deposition from the gas phase, and diffusion chromium plating with subsequent titanium alloys. The results are presented as a comprehensive analysis of coatings: metallographic, micro-X-ray spectral, X-ray phase, durometric, heat resistance, and wear resistance. It is established that multilayer protective coatings are formed as a result of treatments. It is shown that the coatings consist of carbide and nitride zones, intermetallic, and an Al2O3 layer outside the coating. The coatings have been found to contain barrier layers that prevent aluminum from penetrating the substrate. The maximum microhardness is typical for layers based on titanium carbide—30.3–35.5 GPa and titanium nitride—22.0–22.6 GPa, heat-resistant steels AISI W1-7 at a temperature of 900 °C in 4.2–8.5 times and wear resistance under sliding friction without lubrication up to 5.4 times compared to samples without treatment.Item Electric-Spark Alloying of Metal Surfaces with Graphite(G. V. Kurdyumov Institute for Metal Physics of the N.A.S. of Ukraine, 2022) Tarelnyk, V. B.; Гапонова, Оксана Петрівна; Гапонова, Оксана Петровна; Haponova, Oksana Petrivna; Konoplianchenko, Ye.V.The article reviews and analyses the current scientific research in the field of surface treatment of metal surfaces with concentrated energy fluxes (CEF) — the electric-spark (in the literature, known also as electrospark) alloying (ESA), which makes it possible to obtain surface structures with unique physical, mechanical and tribological properties at the nanoscale. The ESA method with a graphite electrode (electrospark carburizing — EC) is based on the process of diffusion (saturation of the surface layer of a part with carbon), and it is not accompanied by an increase in the size of the part. In this article, the influence of the EC parameters on the quality of the carburized layer is investigated. The microstructural analysis shows that the three characteristic zones could be distinguished in the structure: the carburized (‘white’) layer, the finely dispersed transition zone with fine grain, and the base metal zone. The analysis of the results of the durometric studies of the coatings is carried out. To achieve the required parameters of dimensional accuracy and roughness of the working surface of the part after the EC process, it is necessary to use the method of non-abrasive ultrasonic finishing (NAUF). In addition, because of applying the NAUF method, the surface roughness is decreased, the tensile stresses are changed to the compressive ones, and the fatigue strength is increased too. In addition, to reduce the roughness of the treated surface, it is proposed to apply the EC technology in stages, reducing the energy of the spark discharge at each subsequent stage. In order to increase the quality of the carburized layer obtained by the EC process, it is proposed to use a graphite powder, which is applied to the treated surface before alloying. The comparative analysis shows that, after the traditional EC process at Wp = 4.6 J, the surface roughness of steel 20 is Ra = 8.3–9.0 μm, and after the proposed technology, Ra = 3.2–4.8 μm. In this case, the continuity of the alloyed layer increases up to 100%; there increases the depth of the diffusion zone of carbon up to 80 μm as well as the microhardness of the ‘white’ layer and its thickness, which increase up to 9932 MPa and up to 230 μm, respectively. The local micro-x-ray spectral analysis of the obtained coatings shows that, at the EC process carried out in a traditional way, the applying Wp = 0.9, 2.6, 4.6 J provides the formation of the surface layers with high-carbon content depths of 70, 100, 120 μm, respectively, and with the use of a graphite powder, they are of 80, 120, 170 μm. While deepening, the amount of carbon is decreasing from 0.72–0.86% to the carbon content in the base metal — 0.17–0.24%. In the near-surface layer formed with the use of the new technology, the pores are filled with free graphite, which could be used as a solid lubricant to improve the operating characteristics of the friction-pairs parts processed thereby.Item Wear Resistance Improvement of Linear Block-Polyurethanes Under Conditions of Liquid Friction(Sciendo, 2021) Panda, A.; Anisimov, V.M.; Anisimov, V.V.; Дядюра, Костянтин Олександрович; Дядюра, Константин Александрович; Diadiura, Kostiantyn OleksandrovychA significant disadvantage of parts made of linear block polyurethanes under conditions of friction contact in the presence of an aqueous medium is the intensification of hydrolysis processes and decrease in volume strength. It was proposed to slow down the hydrolysis of polyurethanes in three ways: by directed changes in chemical struc-ture, by electromagnetic radiation of different intensities and by creation of composite materials, based on the principle of additional intermolecular crosslinking at the manufacturing and hot processing stages. The conditions for the formation of a smooth wear-resistant surface that protects the material from rapid destruction are re-vealed.Item Increasing of wear resistance of linear block-polyurethanes by thermal processing methods(MM Science Journal, Czech Republic, 2021) Panda, A.; Anisimov, V.M.; Anisimov, V.V.; Дядюра, Костянтин Олександрович; Дядюра, Константин Александрович; Diadiura, Kostiantyn Oleksandrovych; Pandova, I.A significant imperfection of parts made from linear block polyurethanes under conditions of friction contact in the presence of water medium is an intensification of hydrolysis processes and reduction of bulk strength. In order to slow down the hydrolysis process, samples of the polyurethanes were subjected to three types of thermal impacts: thermal processing during some time, infrared and laser irradiation. It has been established that processing in thermal fields of different intensity allows 5-10 times increase of wear resistance of these materials during friction in water medium.Item About wear resistance of linear block-polyurethanes(MM Publishing, 2020) Anisimov, V.M.; Anisimov, V.V.; Panda, A.; Pandova, I.; Дядюра, Костянтин Олександрович; Дядюра, Константин Александрович; Diadiura, Kostiantyn OleksandrovychLinear block-polyurethanes (BPU) are finding more and more practical applications in industry, and their recipe range is rapidly expanding. It is shown that the evaluation of the tribotechnical characteristics of BPU depending on hardness, as suggested by ISO 16365-1:2014 P1, is inaccurate and requires further research to establish the relationship between structure and properties of polyurethanes, taking into account their chemical structure and the type of initiaal components. The dependences of the tribotechnical characteristics of linear block-polyurethanes under friction with steel without external lubrication and in the liquid on the parameters of structural organization of the polymer were studied: at the molecular level (oligooethers, oligoesters), at the topological level (change in the molecular weight of oligomers from 500 to 2000), at supramolecular level (influence of crystallinity), at the morphological level (content of hard phase). The change in the roughness of steel counterbody during friction of polyurethanes with the content of hard blocks 20%, 50%, and 70% was also studied. A method is proposed for increasing the wear resistance of polyurethanes by thermal diffusion saturation of the surface with silicon carbide particles.Item Abrasion Resistance of S235, S355, C45, AISI 304 and Hardox 500 Steels with Usage of Garnet, Corundum and Carborundum Abrasives(Advances in Science and Technology, 2019) Szala, M.; Szafran, M.; Macek, W.; Марченко, Станіслав Вікторович; Марченко, Станислав Викторович; Marchenko, Stanislav Viktorovych; Hejwowski, T.В статті містяться результати випробувань основних типів сталей при терті по нежорстко закріплених частинках абразивуItem Structure and Mechanical Properties of Multilayered Nanostructured TiN/ZrN Ion-plasma Coatings(Sumy State University, 2015) Бондар, Олександр В`ячеславович; Бондарь, Александр Вячеславович; Bondar, Oleksandr Viacheslavovych; Postolnyi, B.O.; Grankin, S.S.; Beresnev, V.M.; Stolbovoy, V.A.; Zhollybekov, B.; Koltunowicz, T.N.Multilayered coatings based on TiN/ZrN with different thickness of bilayers were deposited on steel substrates using vacuum arc deposition of a cathodes (C-PVD method). Thickness of bilayer strongly depended on deposition conditions and varied in the range 39 – 305 nm, total thickness of the coatings were 11-19 μm. Mechanical and tribotechnical characteristics of the coatings were investigated in the paper as well as its microstructure. Influence of the bilayer thickness on the properties of the coatings were explored.Item Surface layers by wear tests of particulate metal matrix composites(Видавництво СумДУ, 2011) Bykov, P.A.; Chernysheva, T.A.; Kobeleva, L.I.The dry sliding wear behaviour of varying weight fraction of SiC particles reinforced AK12M2MgN aluminum alloy metal matrix composites (MMCs) fabricated by a vortex method was investigated using a pin-on-disk tester CETR UMT. The effect of SiC particle content on the friction coefficient and wear resistance has been evaluated. The formation on friction surface of mechanical mixed layers consisting of debris and fragmented SiC particles was indentified using a optical and a scanning electron microscopes. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/20526