Automatic Welding, 2023, №04



2023 №04 (07)

DOI of Article 10.37434/as2023.04.08

2023 №04 (01)

---

Avtomaticheskaya Svarka (Automatic Welding), #4, 2023, pp. 50-56

Fluxless brazing of aluminium alloys by brazing filler metal of Al-Ge system

O.M. Sabadash, S.V. Maksymova

E.O. Paton Electric Welding Institute of the NAS of Ukraine. 11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine. E-mail: office@paton.kiev.ua

The paper gives the results of investigations on fluxless brazing of АD1М, AMts (Al–Mn), AD31 (Al–Mg–Si) aluminium alloys (Al–Mg–Si) with application of Al–25Ge–5Si–5Cu–1.5Mn–0.15Ti brazing filler metal at the temperature of 550 ± 5 °С in the atmosphere of high-purity nitrogen. The results of high-temperature differential thermal analysis were used to determine the solidus and liquidus temperatures of the brazing filler metal. Thermal effects on the derived thermal curve are indicative of the presence of three phases, which correlates with the results of X-ray microprobe analysis. It is shown that the brazing filler metal structure in the initial state is formed by two solid solutions, based on α-Al and β-GeSi and eutectics. Mechanical testing revealed that the short-term strength of the brazed joints is higher than that of the base metal, and fracture occurs in AD1M alloy. Application of steplike cooling of AD31 alloy brazed joint with soaking at the temperature of 500 C promotes increase of shear strength from 84 to 102 MPa. 42 Ref., 1 Tabl., 7 Fig.
Keywords: fluxless brazing, aluminium alloy, germanium brazing filler metal, nitrogen, brazed joint, shear strength


Received: 18.04.2023

References

1. Dudley, D.A., Perry, E.R. (1996) Flux Bath Brazing - an Engineering Technique. Park Thermal INT'L. Corp. 17.
2. Storchay, E.I. (1980) Flux brazing of aluminum. Moscow: Mechanical engineering.
3. Balashov, V.M., Pashkov, I.N., Kaplunov, A.A. (2009) High-temperature filler metal pastes for brazing complex waveguide structures. Questions of radio electronics. General technical series. 3, 89-98.
4. Balashov, V.M., Semenova, E.G., Liu, Ch.Ts. (2010) Resourcesaving technologies for high-temperature brazing of complex-shaped antenna structures in electric furnaces. Proceedings of the IV All-Russian Conference «Radiolocation and Radio Communication» - IRE RAS. November 29 - December 3 (2010) Moscow, 826-838.
5. Yoon, J.S., Lee, S.H., Kim, M.S. (2001) Fabracation and brazeability of three-layer 4343/3003/4343 aluminum clad sheet by rolling. Journal of Materials Processing Technology, 111, 85-89. https://doi.org/10.1016/S0924-0136(01)00517-9
6. Ohashi, Y., Gotou, A., Suzuki, Y., Yanagawa, Y. (2014) Fluxfree Brazing Using Brazing Sheets with Thin Aluminum Layer. Journal of The Japan Institute of Light Metals, 64, 4, 137-141. https://doi.org/10.2464/jilm.64.137
7. Hattori, T., Sakai, S., Sakamoto, A., Fujiwara, C. (1994) Brazeability of Aluminum in Vacuum-Nitrogen Partial-Pressure Atmosphere Brazing. Welding Journal, 10, 233-240.
8. Bernardi, C., Hazotte, A., Siredey-Schwaller, N. Et al. (2014) Microstructure Evolution in an Aluminum Cladded Sheet during Vacuum Brazing. Vacuum Brazing Materials Science Forum, 355-360. https://doi.org/10.4028/www.scientific.net/MSF.790-791.355
9. Yiyou, T., Zhen, T., Jianqing, J. (2013) Effect of Microstructure on Diffusional Solidification of 4343/3005/4343 MultiLayer Aluminum Brazing Sheet. Metallurgical and Materials Transactions A. 44A, 1760-1766. DOI: 10.1007/ s11661-012-1550-5 https://doi.org/10.1007/s11661-012-1550-5
10. Bordo, K., Chakravarthy, V., Peguet, L., Afseth, A. (2018) Electrochemical and microstructural characterization of multiclad aluminium brazing sheets. Corrosion Science, 131, 28-37. https://doi.org/10.1016/j.corsci.2017.11.011
11. Pech-Canul, M.A., Guía-Tello, J.C., Pech-Canul, M.I. et al. (2017) Electrochemical behavior of tube-fin assembly for an aluminum automotive condenser with improved corrosion resistance. Results in Physics, 7, 1760-1777. DOI: 10.1016/j. rinp.2017.05.008 https://doi.org/10.1016/j.rinp.2017.05.008
12. Harksworth, D.K. (2013) Fluxlees brazing of aluminium. Advances in brazing. Science technology and applications, Oxford, 566-585. https://doi.org/10.1533/9780857096500.3.566
13. Childree, D.L. A New Al-Si-Li (1996) Filler Metal that Enhances Brazeability of High-Strength Alloys in CAB and Vacuum. Journal of Materials & Manufacturing, 105, 5, 248-256. https://doi.org/10.4271/960247
14. Ohashi, Y., Gotou, A., Suzuki, Y., Yanagawa Y. (2014) Fluxfree brazing using brazing sheets with thin aluminum layer. Journal of The Japan Institute of Light Metals, 64, 4, 137-141. https://doi.org/10.2464/jilm.64.137
15. Graham, M.E., Hoffman, R.A., Hoffman, M.A. (2005) Fluxless brazing method and method for manufacturing layered materal systems for fluxless brazing. Patent 6959853 US. B23K 31/02. Pub. Data: Nov. 01.2005.
16. Mooij, J.N., Wittebrood, A.J., Olga, J.H.J. (2002) Brazing sheet product and method of its manufacture. Patent 6379818 US B32B 15/20; C25D 5/44; B32K 35/28. Pub. Data: Apr. 30 (2002)
17. Swidersky, H.W. (2001) Aluminium Brazing with Non - corrosive Fluxes - State of the Art and Trends in NOCOLOK Flux Technology. Proceedings of the 6th International Conference on Brazing, High Temperature Brazing and Diffusion Bonding (LÖT 2001), Aachen, Germany (May 2001), 164-169.
18. Yu, C.N., Hawksworth, D., Liu, W., Sekulic, D.P. (2012) Al brazing under severe alterations of the background atmos phere: A new vs. traditional brazing sheet. 5th International Brazing and Soldering Conference, IBSC (2012) April 22- 25, Vegas, Nevada, US: ASM International.
19. Shinoda1, T., Ozawa, S., Kawashima, K. et al. (2022) Flux-Free Brazing of Aluminum Alloys under Ultra-Low Oxygen Partial Pressure through a Zirconia Oxygen Pump. Materials Transactions, 63, 10, 1477-1483. https://doi.org/10.2320/matertrans.MT-M2022078
20. Massalski, T.B. (1990). Вinary Alloy Phase Diagrams, American Society for metals. (Ohiо: Metals Park: ASM International: СD).
21. Schwartz, Mel. M. (2003) Brazing. Second Edition. ASM International ® Materials Park, Ohio.
22. Mills, C.K. (2002) Recommended values of thermophysical properties for selected commercial alloys. Woodhead Publishing Ltd. and ASM International. Cambridge. https://doi.org/10.1533/9781845690144
23. Mondolfo, L.F. (1976) Aluminum Alloys: Structure and Properties, London, UK, P.971. https://doi.org/10.1016/B978-0-408-70932-3.50008-5
24. Belov, N.A. (2009) Phase composition of aluminum alloys. Moscow.
25. Morandoa, C., Fornaro, O. (2018) Morphology and Phase Formation During the Solidification of Al-Cu-Si and Al- Ag-Cu Ternary Eutectic Systems. Materials Research 21(2). https://doi.org/10.1590/1980-5373-mr-2017-0930
26. Chang, S.Y., Tsao, L.C., Li, T.Y., T Chuang. H. &&&(2009) Joining 6061 aluminum alloy with Al-Si-Cu filler metals. Journal of Alloys and Compounds, 488, 174-180. https://doi.org/10.1016/j.jallcom.2009.08.056
27. Humpston, G., Sangha, S.P., Jacson, D.M. (1995) New fillet metals and process for fluxless brazing of aluminium engeneering alloys. Materials Science and Technology, 11, 1161-1167. https://doi.org/10.1179/mst.1995.11.11.1161
28. Jacobson, D.M., Humpston, G., Sangha, S.P. (1996) A new low-melting-point aluminum braze. Welding Journal, 75 (8), 243-250.
29. Peng, C., Zhu, D., Li, K. et al. (2021) Research on a Low Melting Point Al-Si-Cu (Ni) Filler Metal for 6063 Aluminum Alloy Brazing. Applied Sciences, 11, 4296. https://doi.org/10.3390/app11094296
30. Wang, S.S., Cheng, M.D., Tsao, L.C., Chuang, T.H. (2001) Corrosion behavior of Al-Si-Cu-(Sn, Zn) brazing filler metals. Materials Characterization, 47, 401-409. https://doi.org/10.1016/S1044-5803(02)00188-2
31. Song, H., Hellawell, A. (1990) Solidification in the System Al-Ge-Si. The Phase Diagram, Coring Patterns, Eutectic Growth, and Modification. Metallurgical Transactions A, 21A, 734-740. https://doi.org/10.1007/BF02671944
32. Ohmiya, M., Ohsasa, K., Ohmi, T., Kudon, M. (1991) Calculation of Equilibrium Phase Diagram of Al-Ge-Si Ternary System. Bulletin of the Faculty of Engineering Hokkaido University, 156, 11-19.
33. Hayes, F.H., Longbottom R.D., Ahmad, E., Chen G. (1993) On the Al-Si, Al-Ge, and Al-Ge-Si systems and their application to brazing in high power semiconductor devices. Journal Phase Equilibria 14, 425-431. https://doi.org/10.1007/BF02671960
34. Niu, Z., Huang, J., Chen, S., Zhao, X. (2016) Effects of germanium additions on microstructures and properties of Al-Si filler metals for brazing aluminum. Trans. Nonferrous Met. Soc. China, 26, 775-782. https://doi.org/10.1016/S1003-6326(16)64167-5
35. Kayamoto, T., Kim, J.H., Saito, S., Onzawa, T. (1994) Brazing of Al-Mg Alloy and Al-Mg-Si Alloy with Al-Ge Based Filler Metals, Proceedings of Workshop of the Japanese Welding Society, 12, 495-501. https://doi.org/10.2207/qjjws.12.495
36. Niu, Z., Huang, J., Chen, S., Zhao, X. (2017) Influence of Sr additions on microstructure and properties of Al-Si-Ge- Zn filler metal for brazing 6061 aluminum alloy. Journal of Materials Research, 32, 4, 28, 822-830. https://doi.org/10.1557/jmr.2016.467
37. Niu, Z., Huang, J., Yang, H. et al. (2015) Preparation and Properties of a Novel Al-Si-Ge-Zn Filler Metal for Brazing Aluminum. Journal of Materials Engineering and Performance, 24, 2327-2334. https://doi.org/10.1007/s11665-015-1509-y
38. Suzuki, K., Kagayama, M., Takeuchi, Y. (1993) Eutectic phase equilbrium of Al-Si-Zn system and its applicability for lower temperature brazing. Light Metal, 43, 533-538. https://doi.org/10.2464/jilm.43.533
39. Chen, R.Y., Willis, D.J. (2005) The Behavior of Silicon in the Solidification of Zn-55Al-1.6Si Coating on Steel. Metallurgical and Materials Transactions, 36A, 117-128. https://doi.org/10.1007/s11661-005-0144-x
40. Dai, W., Xue, S., Ji, F. et al. (2013) Brazing 6061 aluminum alloy with Al-Si-Zn filler metals containing Sr. International Journal of Minerals, Metallurgy and Materials, 20, 4, 365- 370. https://doi.org/10.1007/s12613-013-0736-1
41. Yang, J., Xue, S., Dai, W., Xue, P. (2015) Saturation phenomenon of Ce and Ti in the modification of Al-Zn-Si filler metal. International Journal of Minerals, Metallurgy and Materials, 22, 2, 184-189. https://doi.org/10.1007/s12613-015-1059-1
42. Zhang, Y., Gao, T., Liu, X. (2014) Influence of Ge content on the microstructure, phase formation and microhardness of hypereutectic Al-Si alloys. Journal of Alloys and Compounds, 585, 442-447. https://doi.org/10.1016/j.jallcom.2013.09.180

---

Advertising in this issue:

---