OBRABOTKAMETALLOV Vol. 24 No. 4 2022 148 MATERIAL SCIENCE References 1. Baldaev L.Kh., Borisov V.N., Vakhalin V.A., Gannochenko G.I., Zatoka A.E., Zakharov B.M., Ivanov A.V., Ivanov V.M., Kalita V.I., Kudinov V.V., Puzryakov A.F., Sborshchikov Yu.P., Khamitsev B.G., Shkol’nikov E.Ya., Yaroslavtsev V.M. Gazotermicheskoe napylenie [Thermal spray]. Moscow, Market DS Publ., 2007. 344 p. ISBN 978-5-7958-0146-9. Chemical composition, structure and microhardness of multilayer high-temperature coatings Nataliya Pugacheva 1, а, *, Yuri Nikolin 2, b, Tatiana Bykova 1, c , Larisa Goruleva 1, d 1 Institute of Engineering Science, Ural Branch, Russian Academy of Sciences, 34 Komsomolskaya str., Yekaterinburg, 620049, Russian Federation 2 Solid Flame Ltd., 54 Lenin Ave., box. 5, Yekaterinburg, 620075, Russian Federation a https://orcid.org/0000-0001-8015-8120, nat@imach.uran.ru, b https://orcid.org/0000-0003-1070-2076, sf.ekb@mail.ru, с https://orcid.org/0000-0002-8888-6410, tatiana_8801@mail.ru, d https://orcid.org/0000-0001-8635-5213, sherlarisa@yandex.ru Obrabotka metallov - Metal Working and Material Science Journal homepage: http://journals.nstu.ru/obrabotka_metallov Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science. 2022 vol. 24 no. 4 pp. 138–150 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2022-24.4-138-150 ART I CLE I NFO Article history: Received: 29 July 2022 Revised: 29 August 2022 Accepted: 15 September 2022 Available online: 15 December 2022 Keywords: Plasma spray Powders Coating Microstructure Dendrites Microhardness Funding The work was carried out on the equipment of the Plastometriya Shared Use Center of the IMASH UB RAS in accordance with the state assignment on the topic No. АААА-А18-118020790145-0. ABSTRACT Introduction. Plasma spraying is one of the modern and effective methods for coatings application for various purposes and compositions. With the help of thermal plasma fl ows, it is possible to spray almost any powder materials (ceramic, metal, metal-ceramic). Plasma spraying of multilayer protective coatings can be successfully used to increase the durability of pierced mandrels, which are the main tool in the production of hollow billets. The purpose of this work is to study the chemical composition, structure, and microhardness of multilayer hightemperature coatings of two different compositions deposited by plasma spraying, which are supposed to be used to increase the durability of pierced mandrels. Materials and research methods. The deposition of multilayer coatings of two compositions was carried out on a plasma-powder spraying unit with contact excitation of an arc discharge UPN-60KM TSP2017. Coatings were obtained by sequential deposition of three layers with different powder compositions. After deposition of all three coating layers, oxidative annealing was carried out at a temperature of 900°C to form a dense scale layer of FeO + Fe2O3 + Fe3O4 on the surface. The chemical composition of the coatings was studied by X-ray microanalysis using a TESCAN scanning electron microscope with an OXFORD attachment. The microstructure of the coatings was studied using a NEOPHOT metallographic microscope. Phase X-ray diffraction analysis was performed on a SHIMADZU diffractometer in Kα-chromium radiation. Microhardness was measured on a LEICA hardness tester at a load of 50 g. Results and discussion. The nature of the distribution of chemical elements over the thickness of the coating, consisting of four layers, is established: an inner metal layer that provides protection against high-temperature corrosion; a transitional metal layer designed to equalize the thermal properties between the layers; α-Fe metal oxide layer and iron oxides and external thermal barrier oxide layer FeO + Fe2O3 + Fe3O4. Coatings are characterized by a non-uniform distribution of structural components and microhardness over its thickness. The microhardness of the inner layer reaches 1,400 HV0.05, the transition layer is 800 HV0.05, and the metal oxide layer is 300 HV0.05. For citation: Pugacheva N.B., Nikolin Yu.V., Bykova T.M., Goruleva L.S. Chemical composition, structure and microhardness of multilayer high-temperature coatings. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science, 2022, vol. 24, no. 4, pp. 138–150. DOI 10.17212/1994-6309-2022-24.4-138-150. (In Russian). ______ * Corresponding author Pugacheva Nataliya B., D.Sc. (Engineering), Associate Professor, Chief Researcher Institute of Engineering Science, Ural Branch, Russian Academy of Sciences, 34 Komsomolskaya str., 620049, Yekaterinburg, Russian Federation Tel.: 8 (343) 362-30-23, e-mail: nat@imach.uran.ru
RkJQdWJsaXNoZXIy MTk0ODM1