Obrabotka Metallov. 2016 no. 4(73)

ОБРАБОТКА МЕТАЛЛОВ № 4 (73) 2016 60 МАТЕРИАЛОВЕДЕНИЕ OBRABOTKAMETALLOV (METAL WORKING AND MATERIAL SCIENCE) N 4 (73), October – December 2016, Pages 52-62 The influence of flowing temperature on the structure and properties of the self-fluxing coatings Kornienko E.E. 1 , Ph.D. (Engineering), Associate Professor, e-mail: kornienko_ee@mail.ru Nikulina A.A. 1 , Ph.D. (Engineering), Associate Professor, e-mail: _aelita27@mail.ru Bannov A.G. 1 , Ph.D. (Engineering), Associate Professor, e-mail: bannov_a@mail.ru Kuz’min V.I. 2 , Ph.D. (Engineering), Associate Professor, e-mail: vikuzmin57@mail.ru Mildebrath M. 3 , Engineer, e-mail: mildebrath@iw.uni-hannover.de Bezrukova V.A. 1 , student, e-mail: vikabezrukova1995@mail.ru Zhoidik A.A. 1 , student, e-mail: sashazhoidik@gmail.com 1 Novosibirsk State Technical University, 20 Prospect K. Marksa, Novosibirsk, 630073, Russian Federation 2 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, 4/1 Institutskaya str., Novosibirsk, 630090, Russian Federation 3 Leibniz University of Hannover, 2 University str., Garbsen, 30823, Germany Abstract The coatings made of self-fluxing powder of the Ni-Cr-Si-B system (Ni – base; 15.1 wt. % Сr; 2.0 wt. % Si; 2.0 wt. % В; 0.4 wt. % С) are deposited on low carbon steel substrate (0.2 wt. % C) by plasma spraying. The study considers the influence of flowing temperature on structure and properties of the specified materials. The samples with coatings are heated in furnace up to 1030, 1050, 1070 and 1100 ºС for 1 hour with the following air cooling. The structure and phase composition of the coatings is investigated using optical and scanning electron microscopy, and X-ray diffractometry. Moreover, the results of microhardness measuring and wear-resistance testing in conditions of sliding friction are demonstrated. X-ray diffractometry showed that the major phases of the coatings before fluxing and after one are the following: γ-Ni, Ni 3 B, CrB и Сr 7 С 3 . The results obtained using optical and scanning electron microscopy brought out that the coatings fluxed at 1030, 1050 and 1070 ºС consist of dendrites of solid solution of Cr, Si and Fe in γ-Ni, Cr 7 C 3 , CrB inclusions and Ni-Ni 3 B, Ni 3 B-Ni 6 Si 2 B eutectics. The coatings fluxed at 1100 ºС consist of dendrites of solid solution of Cr, Si and Fe in γ-Ni, Cr 7 C 3 , CrB 2 inclusions and (γ-Ni)-CrB, Ni-Ni 3 B eutectics. A quantity of hard phases (eutectic, chromium carbides and chromium borides) increases with the rise of temperature. It leads to increase of microhardness and wear-resistance of the coatings. The results of the experiments demonstrate that the coatings fluxed at 1100 ºС have maximum microhardness (953 HV) and wear resistance. Unfortunately, high fluxing temperatures can promote to layer separation. Keywords self-fluxing alloys on the Ni base, Ni-Cr-Si-B system alloys, plasma spraying, fluxing. DOI: 10.17212/1994-6309-2016-4-52-62 References 1. Kolachev B.A., Elagin V.I., Livanov V.A. Metallovedenie i termicheskaya obrabotka tsvetnykh metallov i splavov [Metallurgy and heat treatment of nonferrous metals and alloys]. Moscow, MISIS Publ., 2005. 432 p. ISBN 5-87623-128-2. 2. Zeng Z., Kuroda S., Era H. Comparison of oxidation behavior of Ni-20Cr alloy and Ni-base self-fluxing alloy during air plasma spraying. Surface & Coatings Technology , 2009, vol. 204, iss. 1, pp. 69–77. doi: 10.1016/j. surfcoat.2009.06.036 3. Miguel J.M., Guilemany J.M., Vizcaino S. Tribological study of NiCrBSi coating obtained by different processes. Tribology International , 2003, vol. 36, pp. 181–187. 4. 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.