Burkov A.A. et. al. 2018 Vol. 20 No. 3

OBRABOTKAMETALLOV Vol. 20 No. 3 2018 94 MATERIAL SCIENCE References 1. Ganjeh E., Sarkhosh H. Microstructural, mechanical and fractographical study of titanium-CP and Ti–6Al–4V similar brazing with Ti-based filler. Materials Science and Engineering A , 2013, vol. 559, pp. 119–129. doi: 10.1016/j. msea.2012.08.043. Improvement of Anti-corrosion and Tribotechnical Properties of Ti6Al4VAlloy by Deposition of Spark Ti-Al-Si-C Coatings Alexander Burkov a,* , Sergey Pyachin , b , Nuria Vlasova , c , Ivan Astapov d , Maria Kulik e Institute for Material Studies, Khabarovsk Scientific Center, Far Eastern Branch of Russian Academy of Sciences, 153 Tikhookeanskaya st., Khabarovsk, 680042, Russian Federation a https://orcid.org/0000-0002-5636-4669, burkovalex@mail.ru , b https://orcid.org/0000-0003-0589-0279, pyachin@mail.ru , c https://orcid.org/0000-0003-0198-0912, vlasova64@yandex.ru , d https://orcid.org/0000-0003-2919-2520, immaterial_khv@mail.ru, e https://orcid.org/0000-0002-4857-1887, marijka80@mail.ru Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science. 2018 vol. 20 no. 3 pp. 85–96 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2018-20.3-85-96 Obrabotka metallov - Metal Working and Material Science Journal homepage: http://journals.nstu.ru/obrabotka_metallov ARTICLE INFO Article history : Received: 21 May 2018 Revised: 26 June 2018 Accepted: 05 July 2018 Available online: 15 September 2018 Keywords : Titanium alloy Coating Electrospark deposition Titanium aluminide Silicon carbide Wear resistance Corrosion resistance ABSTRACT Relevance . The titanium alloy Ti6Al4V is widely used in aerospace and medical industries, due to its high specific strength, ductility and corrosion resistance. However, the use of Ti6Al4V alloy in some important structural elements is limited due to its relatively low oxidation resistance and high viscosity during wear. The purpose of the study is to investigate the increase in the oxidation resistance of the titanium alloy Ti6Al4V at high temperatures and dry sliding wear, by applying Ti-Al-Si-C composite protective layers. The coatings obtained by the method of spark deposition using electrodes made in the form of rods by sintering Ti 3 Al aluminide powders with 5-15 wt% SiC carbide additives are investigated. Materials and methods. The phase composition of the coatings is studied by X-ray diffraction analysis. Corrosion tests of the coatings are presented by a study of oxidation resistance at a temperature of 900 ° C for ~ 62 hours and potentiodynamic tests in 3.5% NaCl solution. The microhardness of the deposited layers is determined by Vickers indentation at the load of 0.5 N. The wear resistance and coefficient of friction of the coatings are determined in the dry sliding mode versus to high-speed steel R6M5 at a sliding speed of 12 m / s and a load of 25 N. Results and discussion . Electrode materials with addition of Ti 3 Al intermetallide contained titanium carbide TiC, titanium silicide TiSi 2 and complex carbide Ti 4 Al 2 C 2 . According to the analysis of kinetic mass transfer curves, the optimum deposition time of the spark Ti-Al-Si-C coatings for Ti6Al4V alloy is 4 min/cm 2 . It is established that the basis of coatings is composed of intermetallides Ti 3 Al and TiAl. In addition, it includes TiC carbide and Ti 5 Si 3 titanium silicide, the content of which increases with increasing the concentration of the SiC additive in the initial composition of the powder mixture. The oxidation resistance of Ti6Al4V alloy with a composite coating obtained from Ti 3 Al with the addition of 5 wt% silicon carbide was 2.7 times higher than that without coating. According to the results of potentiodynamic tests, it was concluded that Ti 3 Al coating with a 15 wt% SiC additive had the best anticorrosion characteristics. This coating allows decreasing the wear rate of the titanium alloy Ti6Al4V from 1.9 ∙ 10 -4 to 1.2 ∙ 10 -6 mm 3 /(Nm). The hardness of coatings was in the range of 10...22 GPa. For citation: BurkovA.A., Pyachin S.A., Vlasova N.M., Astapov I.A., Kulik M.A. Improvement of anti-corrosion and tribotechnical properties of Ti6Al4V alloy by deposition of spark Ti-Al-Si-C coatings. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science , 2018, vol. 20, no. 3, pp. 85–96 . doi:10.17212/1994-6309-2018-20.3-85-96. (In Russian). ______ * Corresponding author Burkov Alexander A. , Ph.D. (Physics), Institute for Material Studies, Khabarovsk Scientific Center, Far Eastern Branch of Russian Academy of Sciences, 153 Tikhookeanskaya st., 680042, Khabarovsk, Russian Federation Tel.: 8 (914) 1618954, e-mail: burkovalex@mail.ru