Публікації співробітників (ВІТВ НТУ "ХПІ")
Постійне посилання колекціїhttps://repository.kpi.kharkov.ua/handle/KhPI-Press/21692
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Документ Study of the influence of oxidizing parameters on the composition and morphology of Al₂O₃·CoOₓ coatings on AL25 alloy(Технологический центр, 2018) Karakurkchi, A.; Sakhnenko, M.; Ved, M.The influence of operating parameters of plasma-electrolytic oxidation in diphosphate cobalt-containing electrolyte on the process of formation of oxide coatings on alumosilicon alloy AL25 (GOST 1583) was studied. It was shown that inclusion of cobalt into the composition of surface oxide layers leads to a change of morphology and topography of the surface. Variation of current density and PEO time allows flexible control of the process of incorporation of the catalytic component into the matrix of oxide of basic metal. It was shown that at an increase in oxidation time, cobalt content in the surface oxide layer increases. The rational mode of plasma-electrolytic treatment of piston alloy in diphosphate electrolyte for obtaining oxide coatings, enriched with cobalt, was substantiated. It is advisable to perform formation of PEO-coatings on AL25 with developed globular-mosaic surface, maximum cobalt content, with minimizing impurities in the range of current densities of 3–5 A/dm² within 20–40 min. The obtained cobalt-containing oxide coatings can be used in the air and water purification systems, specifically, for intracylinder catalysis of gas emissions of internal combustion engines.Документ Study into formation of cobalt-containing peo-coatings on AK12M2MgN from a pyrophosphate electrolyte(Технологический центр, 2017) Karakurkchi, A.; Sakhnenko, M.; Ved, M.; Horokhivskyi, A.; Galak, A.We studied the process of formation of cobalt-containing oxide coatings using plasma-electrolytic oxidizing of the aluminum alloy AK12M2MgN in pyrophosphate electrolytes. It was established that the use of given type solutions contributes the homogenization of silumin surface and creates preconditions for the dopants incorporation to the growing oxide coating. It is shown that PEO parameters depend on the concentration ratio of cobalt sulfate and potassium pyrophosphate in a working solution. Based on the results of experimental study, we demonstrated the ways to control the structure and surface morphology of cobalt-containing PEO coatings through the variation in the concentrations of electrolyte components. The composition of a pyrophosphate electrolyte for the formation of oxide PEO-coatings with a high cobalt content and developed surface morphology is substantiated. It is noted that the obtained oxide coatings could be used in catalytic reactions in order to decompose natural and technogenic toxicants.Документ Increasing the efficiency of intra-cylinder catalysis in diesel engines(Украинский государственный химико-технологический университет, 2017) Parsadanov, I. V.; Sakhnenko, N. D.; Ved, M. V.; Rykova, I. V.; Khyzhniak, V. A.; Karakurkchi, A. V.; Gorokhivskiy, A. S.The data of research done to systemize and choose scientific fields and search for the rational ways of an increase in the efficiency of intra-cylinder catalysis in diesel engines have been given. The use of base metal oxides and composite oxides of transition metals as the coatings for the piston combustion chamber has been substantiated. This allows us to control chemical reaction rates and reduce the formation of toxic substances. When selecting the scientific fields and rational practical ways of an increase in the efficiency of intra-cylinder catalysis in diesel engines chemical, physical and technological factors were taken into consideration. The formation of catalytic coatings based on the oxides of transition metals (Mn, Co) was provided using the plasma-electrolytic oxidizing on the Al25 alloy. These included both individual manganese and cobalt oxides and the mixed oxides of both metals. The investigation of catalytic coatings of the combustion chamber in the diesel engine piston on the basis of manganese and cobalt oxides and mixed oxides enabled the establishment of a maximum catalytic effect when cobalt oxides were used. The prototype diesel test data showed that the fuel rate in this case is decreased by 4 to 6 %, NOx emissions were reduced by 14 to 15 % and carbon oxide emissions were reduced by 20 through 25 %.