Військовий інститут танкових військ НТУ "ХПІ"

Зараз показуємо 1 - 3 з 3

Synthesis of catalytic cobalt-containing coatings on alloy AL25 surface by plasma electrolytic oxidation
(Інститут хімії поверхні ім. О. О. Чуйка НАН України, 2017) Ved, M. V.; Karakurkchi, A. V.; Sakhnenko, N. D.; Gorohivskiy, A. S.
The study aims at the investigation of the influence of electrolyte composition and plasma electrolytic oxidation modes on the composition and morphology of a mixed aluminum and cobalt oxides at the AL25 alloy. Composition, morphology and surface roughness of the oxide systems are examined by scanning electron microscopy, X-ray analysis and atomicforce microscopy. Mixed oxide coatings Al₂O₃·CoOₓ formed from the diphosphate electrolytes at various concentration ratio diphosphate/cobalt sulfate contain cobalt of 8-30 at. % (in terms of metal) in the matrix of alumina. Plasma electrolytic oxidation in a two-stage mode of the incident power provided formation of strongly adhered coatings characterized by non-stoichiometry ratio of cobalt and oxygen as well aslow content of silicon in deposits. Obtained mixed oxide systems have developed surface with alternating the spheroid and torus-shaped structures which is associated with a large number of catalytic sites. They exhibit catalyticbehavior in the model reactions of CO conversion to CO₂ and benzene oxidation not inferior to the contacts with noble metals. The coatings Al₂O₃·CoOₓ contribute to fuel economy and improve the environmental performance of the internal combustion engine thus can be recommended for use in the neutralization of gas emissions systems and as coatings for pistons of combustion chamber.
Cobalt and manganese oxide catalytic systems on valve metals in ecotechnologies
(Kyiv National University of Technologies and Design, 2017) Karakurkchi, A. V.; Sakhnenko, M. D.; Ved, M. V.; Gorohivskiy, A. S.; Galak, O.; Menshov, S.; Matykin, O.
The paper discusses the preparation of cobalt and manganese oxide catalytic systems on valve metals (aluminum and titanium alloys) for eco-technologies. Oxide catalysts with d-metals based on aluminum are widely used for reduce the toxic gases emission from internal combustion engines. Catalysts based on Titania doped with transition metal oxides are also widely used in the heterogeneous and especially photo-catalysis. The higher catalytic properties in this case are demonstrated by the nano-structured oxide systems with developed surface both on aluminum and titanium alloys. From the point of view of the application convenience, better technological forms of a catalyst are the thin-film oxide coatings, formed directly on the metal substrate by the method of plasma-electrolytic oxidizing. It is considered the features of the conversion coatings formation on aluminum and titanium alloys by plasma electrolytic oxidation in alkaline electrolytes. The effect both the concentration and ratio of the electrolyte components and processing conditions on the composition and the morphology of the surface layers is studied. The difference in the plasma oxidation parameters of aluminum and titanium alloys is attributed with the various specific electric resistance of matrix metal as well as the alloying elements oxides. The oxides’ composition influence on the surface relief and their properties is investigated. The factors influenced on the catalytic properties of single and mixed oxide systems are established and the prospects for their use in technology of neutralization of toxic substances are discussed.
Nanostructured catalytic cobalt containing PEO-coatings on alloy AL25
(Chuiko Institute of Surface Chemistry of National Academy of Sciences of Ukraine, 2016) Karakurkchi, A. V.; Sakhnenko, N. D.; Ved, M. V.; Gorohivskiy, A. S.

Військовий інститут танкових військ НТУ "ХПІ"

Переглянути

Фільтри

Налаштування

Сортувати за

Результатів на сторінку

Результати пошуку