Automatic Welding, 2021, №05



2021 №05 (06)

DOI of Article 10.37434/as2021.05.07

2021 №05 (08)

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Avtomaticheskaya Svarka (Automatic Welding), #5, 2021, pp. 46-50

Analysis of the properties of electron beam welded joints of aluminium lithium alloy latest generation

Mir. Sahul¹, Mar. Sahul², Ľ. Čaplovič², M. Marônek¹, I. Klochkov³, S. Motrunich³

¹Slovak University of Technology in Bratislava, Faculty of Materials Science and Technology in Trnava, Department of Welding and Joining of Materials, J. Bottu 25, 917 24 Trnava, Slovakia. E-mail: miroslav.sahul@stuba.sk
²Slovak University of Technology in Bratislava, Faculty of Materials Science and Technology in Trnava, Institute of Materials Science, J. Bottu 25, 917 24 Trnava, Slovakia
³E.O. Paton Electric Welding Institute of the NAS of Ukraine, 11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine. E-mail: office@paton.kiev.ua

Electron beam welded joints made on AW2099 aluminium lithium alloy with the thickness of 4 mm were analysed. The third generation of aluminium lithium alloys was developed to improve the drawbacks of the second one. Various electron beam welding parameters (beam current, welding speed) were tested. Accelerating voltage was constant, i.e., 55 kV. Defect free welded joints were produced under optimized welding parameters. Weld metal microstructure and welded joints mechanical properties were investigated. Microstructure of weld metal matrix consists of α-aluminium solid solution. Inter-dendrite areas were enriched in alloying elements due to segregation. Narrow equiaxed zone was observed at the location close to the fusion boundary being characteristic for welded joints made on aluminium lithium alloys. The character of the grains changed in the direction towards weld metal centre to columnar dendritic and equiaxed dendritic. Microhardness values reduction in the weld metal was observed which is associated to the dissolution of strengthening precipitates. 22 Ref., 1 Tabl., 9 Fig.
Keywords: AW2099 aluminium lithium alloy, electron beam welding, equiaxed zone, scanning electron microscopy, drop of microhardness


Received:22.04.2021

References

1. Xiao, R., Zhang, X. (2014) Problems and issues in laser beam welding of aluminum-lithium alloys. J. Materials. Proc. Technology, 16, 166-175. https://doi.org/10.1016/j.jmapro.2013.10.005
2. Gao, Ch., Gao, R., Ma, Y. (2015) Microstructure and mechanical properties of friction spot welding aluminiumlithium 2A97 alloy. Mater. Des., 83, 719-727. https://doi.org/10.1016/j.matdes.2015.06.013
3. Han, B., Tao, W., Chen, Y., Li, H. (2017) Double-sided laser beam welded T-joints for aluminium-lithium alloy aircraft fuselage panels: Effects of filler elements on microstructure and mechanical properties. Opt. Laser Technol., 93, 99-108. https://doi.org/10.1016/j.optlastec.2017.02.004
4. Lee, H.-S., Yoon, J.-H., Yoo, J.-T., No, K. (2016) Friction stir welding process of aluminum-lithium alloy 2195. Procedia Eng., 149, 62-66. https://doi.org/10.1016/j.proeng.2016.06.639
5. Ma, Y.E., Xia, Z.C., Jiang, R.R., Li, W.Y. (2013) Eff ect of welding parameters on mechanical and fatigue properties of friction stir welded 2198 T8 aluminum-lithium alloy joints. Eng. Fract. Mech., 114, 1-11. https://doi.org/10.1016/j.engfracmech.2013.10.010
6. Zhang, F., Shen, J., Yan, X.-D. et al. (2014) Homogenization heat treatment of 2099 Al-Li alloy. Rare Met., 33, 28-36. https://doi.org/10.1007/s12598-013-0099-9
7. Tao, Y., Ni, D.R., Xiao, B.L. et al. (2017) Origin of unusual fracture in stirred zone for friction stir welded 2198-T8 Al-Li alloy joints. Mater. Sci. Eng., A 693, 1-13. https://doi.org/10.1016/j.msea.2017.03.079
8. Rajan, R., Kah, P., Mvola, B., Martikainen, J. (2016) Trends in aluminium alloy development and their joining methods. Rev. Adv. Mater. Sci., 44, 383-397.
9. Dursun, T., Soutis, C. (2014) Recent developments in advanced aircraft aluminium alloys. Mater. Des., 56, 862-871. https://doi.org/10.1016/j.matdes.2013.12.002
10. Romios, M., Tiraschi, R., Ogren, J.R., Babel, H.W. (2005) Design of multistep aging treatments of 2099 (C458) Al-Li alloy. J. Mater. Eng. Perform., 14, 641-646. https://doi.org/10.1361/105994905X64594
11. Wang, G., Zhao, Y., Hao, Y. (2018) Friction stir welding of highstrength aerospace aluminium alloy and application in rocket tank manufacturing. J. of Mater. Sci. and Technology, 34, 73-91. https://doi.org/10.1016/j.jmst.2017.11.041
12. Poklyatsky, A.G., Knysh, V.V., Klochkov, I.N., Motrunich, S.I. (2016) Features and advantages of the process of friction stir welding of butt joints of sheet aluminium-lithium alloys. The Paton Welding J., 6, 93-98. https://doi.org/10.15407/as2016.06.15
13. Milagre, M.X., Mogili, N.V., Donatus, U. et al. (2018) On the microstructure characterization of the AA2098-T351 alloy welded by FSW. Mater. Charact., 140, 233-246, DSC vyzera byt fajn. https://doi.org/10.1016/j.matchar.2018.04.015
14. Li, W.Y., Chu, Q., Yang, X.W. et al. (2018) Microstructure and morphology evolution of probeless friction stir spot welded joints of aluminum alloy. J. of Materials Proc. Technology, 252, 69-80. https://doi.org/10.1016/j.jmatprotec.2017.09.003
15. Knysh, V.V., Klochkov, І.М., Motrunich, S.I., Poklyatsky, A.G. (2021)Infl uence of irregular cyclic load on fatigue resistance of thinsheet welded joints of heat-strengthened aluminium alloys. The Paton Welding J., 1, 9-13. https://doi.org/10.37434/as2021.01.02
16. de Castro, C.C., Plaine, A.H., Dias G.P. et al. (2018) Investigation of geometrical features on mechanical properties of AA2198 refi ll friction stir spot welds. J. Manuf. Processes, 36, 330-339. https://doi.org/10.1016/j.jmapro.2018.10.027
17. Hatamleh, O., Rivero, I.V., Swain S.E. (2009) An investigation of the residual stress characterization and relaxation in peened friction stir welded aluminium-lithium alloy joints. Mater. Des., 30, 3367-3373. https://doi.org/10.1016/j.matdes.2009.03.038
18. Motrunich, S., Klochkov, I., Poklaytsky, A. (2020)High cycle fatigue behaviour of thin sheet joints of aluminium-lithium alloys under constant and variable amplitude loading. Weld World, 64, 1971-1979. https://doi.org/10.1007/s40194-020-00976-2
19. Weglowski, M.St., Blacha, S., Phillips, A. (2016) Electron beam welding - Techniques and trends - Review. Vacuum, 130, 72-92. https://doi.org/10.1016/j.vacuum.2016.05.004
20. Cui, L., Li, X., He, D. et al. (2012) Eff ect of Nd:YAG laser welding on microstructure and hardness of an Al-Li based alloy. Mater. Charact., 71, 95-102. https://doi.org/10.1016/j.matchar.2012.06.011
21. Chen, G., Yin, Q., Zhang, G., Zhang, B. (2020) Fusiondiff usion electron beam welding of aluminium-lithium alloy with Cu nano-coating. Mater. Des., 188, 108439. https://doi.org/10.1016/j.matdes.2019.108439
22. Chen, G., Yin, Q., Zhang, G., Zhang, B. (2020) Underlying causes of poor mechanical properties of aluminum-lithium alloy electron beam welded joints. J. Manuf. Process., 50, 216-223. https://doi.org/10.1016/j.jmapro.2019.12.052

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