On the problem of tool destruction when obtaining fixed joints of thick-walled aluminum alloy blanks by friction welding with mixing

OBRABOTKAMETALLOV Vol. 23 No. 3 2021 81 EQUIPMENT. INSTRUMENTS On the problem of tool destruction when obtaining fi xed joints of thick-walled aluminum alloy blanks by friction welding with mixing Kirill Kalashnikov 1, a,* , Andrey Chumaevskii 1, b , Tatiana Kalashnikova 1, c , Aleksey Ivanov 1, d , Valery Rubtsov 1, e , Evgeny Kolubaev 1, f , Vladimir Bakshaev 2, g 1 Institute of Strength Physics and Materials Science of Siberian Branch of Russian Academy of Sciences, 2/4 pr. Akademicheskii, Tomsk, 634055, Russian Federation 2 SESPEL Cheboksary enterprise, CJSC, 36 Leningradskaya st., Cheboksary, 428021, Chuvash Republic, Russian Federation a https://orcid.org/0000-0002-0286-7156, kkn@ispms.tsc.ru , b https://orcid.org/0000-0002-1983-4385, tch7av@gmail.com, c https://orcid.org/0000-0002-0388-4011 , gelombang@ispms.tsc.ru , d https://orcid.org/0000-0001-8959-8499, ivan@ispms.tsc.ru, e https://orcid.org/0000-0003-0348-1869, rvy@ispms.tsc.ru , f https://orcid.org/0000-0001-7288-3656, eak@ispms.tsc.ru, g https://orcid.org/0000-0001-9777-0164, bakshaevva@mail.ru Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science. 2021 vol. 23 no. 3 pp. 72–83 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2021-23.3-72-83 Obrabotka metallov - Metal Working and Material Science Journal homepage: http://journals.nstu.ru/obrabotka_metallov ARTICLE INFO Article history : Received: 15 June 2021 Revised: 30 June 2021 Accepted: 30 July 2021 Available online: 15 September 2021 Keywords : Friction stir welding Welding tool Aluminum alloy Destruction Funding The results were obtained in the framework of the Integrated Project “Establishment of production of high- tech large-sized equipment for intelligent adaptive friction stir welding for the aerospace and transport industries of the Russian Federation” (Agreement No. 075-11-2019-033 dated November 22, 2019) implemented by the NSTU and ISPMS SB RAS at the fi nancial support of the Ministry of Education and Science of the Russian Federation as part of Decree of the Government of the Russian Federation No. 218 dated April 09, 2010. Acknowledgements Research were conducted at core facil- ity “Structure, mechanical and physical properties of materials”. ABSTRACT Introduction. Among the technologies for manufacturing rocket and aircraft bodies, marine vessels, and vehicles, currently, more and more attention is paid to the technology of friction stir welding (FSW). First of all, the use of this technology is necessary where it is required to produce fi xed joints of high-strength aluminum alloys. In this case, special attention should be paid to welding thick-walled blanks, as fi xed joints with a thickness of 30.0 mm or more are the target products in the rocket-space and aviation industries. At the same time, it is most prone to the formation of defects due to uneven heat distribution throughout the height of the blank. It can lead to a violation of the adhesive interaction between the weld metal and the tool and can even lead to a destruction of the welding tool. The purpose of this work is to reveal regularities of welding tool destruction depending on parameters of friction stir welding process of aluminum alloy AA5056 fi xed joints with a thickness of 35.0 mm. Following research methods were used in the work: the obtaining of fi xed joints was carried out by friction welding with mixing, the production of samples for research was carried out by electric erosion cutting, the study of samples was carried out using optical metallography methods. Results and discussion. As a result of performed studies, it is revealed that samples of aluminum alloy with a thickness of 35.0 mm have a heterogeneous structure through the height of weld. There are the tool shoulder effect zone and the pin effect zone, in which certain whirling of weld material caused by the presence of grooves on tool surface is distinctly distinguished. It is shown that the zone of shoulders effect is the most exposed to the formation of tunnel-type defects because of low loading force and high welding speeds. It is revealed that tool destruction occurs tangentially to the surface of the tool grooves due to the high tool load and high welding speeds. For citation: Kalashnikov K.N., Chumaevskii A.V., Kalashnikova T.A., Ivanov A.N., Rubtsov V.E., Kolubaev E.A., Bakshaev V.A. On the problem of tool destruction when obtaining fi xed joints of thick-walled aluminum alloy blanks by friction welding with mixing. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science , 2021, vol. 23, no. 3, pp. 72–83. DOI: 10.17212/1994-6309-2021-23.3-72-83. (In Russian). ______ * Corresponding author Kalashnikov Kirill N. , Junior Research Of fi cer Institute of Strength Physics and Materials Science of Siberian Branch of Russian Academy of Sciences, 2/4, pr. Akademicheskii, 634055, Tomsk, Russian Federation Tel.: 8 (382) 228-68-63, e-mail: kkn@ispms.tsc.ru