Properties ensuring of aircraft titanium structures joints obtained by fuse welding identical to the basic metal properties

DOI: 10.34759/vst-2021-3-218-227

Аuthors

Murav’ev V. I.^*, Bakhmatov P. V.^**, Grigor’ev V. V.^***

Komsomolsk-on-Amur State University (KnASU), 27, Lenin str., Komsomolsk-on-Amur, 681013, Russia

*e-mail: vmuravyev@mail.ru
**e-mail: mim@knastu.ru
***e-mail: grigorev.vlv@gmail.com

Abstract

Modern aerial vehicles are dynamically developing both structurally and in the field of employing the newest materials, which is being associated with the basic requirements imposed on them, such as ensuring minimum weight and increased strength properties at high alternating loads. The most suitable metallic material meeting the above-said requirements is titanium alloys, which are being actively applied in the aerial vehicles framings. Since the 70s of the last century, the aircraft structural elements have been assembled by welding, while all-in-one joints herewith must meet the unified requirements developed for the industry. As a rule, three welding methods are being employed to form permanent joints in the aircraft building industry. They are welding with a non-melting electrode in a protective gas environment (both traditional and submerged tungsten electrode), and electron beam welding.

An immense experience has been accumulated on the these methods application in the aircraft building industry, nevertheless, each of the methods has a number of unrealized potential opportunities to improve the permanent joints quality in the field of warping reducing, crack and pore forming, and mechanical properties enhancing to the level of the base metal. The article presents the results of analysis of publications and the authors’ own research on the above-mentioned problems. The welding modes impact, the introduction of an additional heat source, and mixing intensification of a liquid-metal bath when applying the basic welding methods are considered.

The authors found that porosity elimination occurred with the life span increase of the welding bath, but, with this, the geometry of the weld seam changes dramatically, strength properties decrease up to 15% compared to the base metal.

With the additional heat source introduction, the bubbles degasification occurs, and the permanent joint properties similar to the base material are being obtained.

Currently, the development of electronic control systems and parameters tracking of the permanent joints forming process allows oscillating both the trajectory and welding modes, which allows in its turn introduction of pointed dosing of both energy and welding material into a specific point of the welding bath.

Due to the unique properties of metal melting, the possibility of oscillation allows causing the welding bath to overheating up to boiling temperatures, and cause its intensive mixing, which contributes also to obtaining satisfactory permanent joints with the properties similar to the base metal.

Keywords:

titanium alloys, all-in-one joints, group assembly, electron beam welding, automatic argon arc welding, aerial vehicles’ load bearing elements

References

1. Bratukhin A.G., Murav’ev V.I., Dolotov B.I. et al. Aviatsionnaya promyshlennost’, 1997, no. 3-4, pp. 3-9.

2. Murav’ev V.I., Bakhmatov P.V., Frolov A.V. Perspektivnye metallurgicheskie i tekhnologicheskie protsessy proizvodstva, povyshayushchie nadezhnost’ izdelii iz konstruktsionnykh materialov (Prospective metallurgical and technological production processes, obtaining reliable products from structural materials), Komsomol’sk-na-Amure, KnAGTU, 2016, 330 p.

3. Arzamasov B.N., Brostrem V.A., Bushe N.A. et al. Konstruktsionnye materialy. Spravochnik (Structural materials. Reference Book), Moscow, Mashinostroenie, 1990, 688 p.

4. Gurevich S.M., Zamkov V.N., Blashchuk V.E. et al. Metallurgiya i tekhnologiya svarki titana i ego splavov (Metallurgy and technology of titanium and its alloys welding), Kiev, Naukova dumka, 1986, 240 p.

5. Redchits V.V., Frolov V.A., Kazakov V.A., Lukin V.I. Poristost’ pri svarke tsvetnykh metallov (Porosity at nonferrous metals welding), Moscow, Tekhnologiya mashinostroeniya, 2002, 448 p.

6. Murav’ev V.I. Metallovedenie i termicheskaya obrabotka metallov, 2005, no. 7(601), pp. 30-37.

7. Dolotov B.I. Svarka pogruzhennym vol’framovym elektrodom (Weldin by tungsten electrode immersion), Moscow, Mashinostroenie, 2004, 208 p.

8. Paton B.E., Lobanov L.M., Lysak V.V. et al. Avtomaticheskaya svarka, 2014, no. 9(735), pp. 7-18.

9. Lozeev G.E., Chernitsyn A.I., Frolov V.V. Avtomaticheskaya svarka, 1977, no. 2, pp. 25-30.

10. Dolotov B.I., Murav’ev V.I., Mar’in B.N. et al. Svarochnoe proizvodstvo, 1996, no. 12, pp. 6-8.

11. Murav’ev V.I., Fizulakov R.A., Mel’nichuk A.F. et al. Metallovedenie i termicheskaya obrabotka metallov, 2005, no. 2, pp. 22-25.

12. Remchukov S.S., Lebedinskii R.N. Laser technologies application specifics while plate heat exchangers developing for small-size gas turbine engines. Aerospace MAI Journal, 2020, vol. 27, no. 2, pp. 90-98. DOI: 10.34759/vst-2020-2-90-98

13. Kar J., Chakrabarti D., Roy S.K., Roy G.G. Beam oscillation, porosity formation and fatigue properties of electron beam welded Ti-6Al-4V alloy. Journal of Materials Processing Technology, 2019, vol. 266, pp. 165-172. DOI: 10.1016/j.jmatprotec.2018.10.040

14. Murav’ev V.I., Bakhmatov P.V., Dolotov B.I. et al. Obespechenie nadezhnosti konstruktsii iz titanovykh splavov (Ensuring the reliability of structures made of titanium alloys), Moscow, Ekom, 2009, 752 p.

15. Shorshorov M.Kh., Meshcheryakov V.N. Fazovye prevrashcheniya i izmeneniya svoistv splavov titana pri svarke. Atlas (Phase transformations and properties changing of titanium alloys while welding. Atlas), Moscow, Nauka, 1973, 160 p.

16. Grabin V.F. Metallovedenie svarki plavleniem (Metal science of fusion welding), Kiev, Naukova dumka, 1982, 416 p.

17. Merkulov V.I., Dolotov B.I., Murav’ev V.I. et al. Patent RU 2133178 C1, 20.07.99.

18. Simonik A.G., Vereshchagin S.I. Svarochnoe proizvodstvo, 1982, no. 3, pp. 13–14.

19. Kosovich V.A., Polupan V.A., Panin A.V., Yarovinskii Yu.L. Svarochnoe proizvodstvo, 1986, no. 9, pp. 14-15.

20. Selyanenkov V.N., Stepanov V.V., Saifiev R.Z. Svarochnoe proizvodstvo, 1980, no. 5, pp. 5-7.

21. Zimina E.G., Shubin V.I., Eiduk Yu.A. Tekhnologicheskie i ekspluatatsionnye svoistva molibdenovykh i vol’framovykh splavov. Sbornik statei, Moscow, VNIITS, 1991, pp. 92-96.

22. Dolotov B.I., Dashkovskii A.A., Murav’ev V.I. et al. Aviatsionnaya promyshlennost’, 1992, no. 8, pp. 46-47.

23. Nazarenko O.K., Kaidalov A.A., Kovbasenko S.N. et al. Elektronno-luchevaya svarka (Electron beam welding), Kiev, Naukova dumka, 1987, 256 p.

24. Fedorov S.S., Tishchenko M.Yu., Shmakov S.V., Zaides S.A. Svarochnoe proizvodstvo, 2016, no. 3, pp. 16-21.

25. Murav’ev V.I., Bakhmatov P.V., Grigor’ev V.V. Specific defects forming features while aircraft bulky titanium structures assembling. Aerospace MAI Journal, 2019, vol. 26, no. 4, pp. 17-27. DOI: 10.34759/vst-2019-4-17-27

26. Kou S., Tsai M.C. Thermal Analysis of GTA Welding Electrodes. Welding research supplement, 1985, vol. 64, no. 9, pp. 266-269. URI: https://app.aws.org/wj/supplement/WJ_1985_09_s266.pdf

27. Ol’shanskaya T.V., Salomatova E.S. Vestnik Permskogo natsional’nogo issledovatel’skogo politekhnicheskogo universiteta. Mashinostroenie, materialovedenie, 2016, vol. 18, no. 4, pp. 169-187. DOI: 10.15593/2224-9877/2016.4.13