The Backing Bar Role in Heat Transfer on Aluminium Alloys Friction Stir Welding

Abstract:

Although new structural and advanced materials have been used in the automotive and aircraft industries, especially lightweight alloys and advanced high strength steels, the successful introduction of such materials depends on the availability of proven joining technologies that can provide high quality and performance joints. Solid-state joining techniques such as Friction Stir Welding (FSW) are a natural choice since their welds are produced at low temperatures, so the low heat input provides limited, slight distortion, microstructural and mechanical degradation. Great effort has currently been devoted to the joining of Al-Cu-Mg and the Al-Mg-Si alloys because of their high strength, improved formability, and application in airframe structures. FSW is a continuous, hot shear, autogenous process involving a non-consumable and rotating tool plunged between two abutting workpieces. The backing bar plays an important role in heat transfer from stir zone (SZ), which can influence the weld microstructure as well as the consolidation of material in the root of the join. This study aims at investigating issues concerning heat generation, within the SZ of friction stir welded aircraft aluminium alloys.

• Periodical: Materials Science Forum (Volumes 636-637)
• Pages: 459-464
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.636-637.459
• Online since: January 2010
• Authors: M.J.C. Rosales, N.G. Alcantara, Jorge Santos, R. Zettler
• Keywords: Backing Bar, Friction Stir Welding (FSW), Heat Transfer

References

[1] Mishra, R. S. Ma, Z. Y. Friction stir welding and processing, Materials Science and Engineering Vol. R50 (2005), pp.1-78.

[2] Zettler, R. Lomolino, S. dos Santos, J. F. Donath, T. Beckmann, F. Lippman, T. Lohwasser, D. A Study on Material Flow in FSW of AA 2024-T351 and AA 6056-T4 Alloys, in 5th International FSW Symposium, Metz, France, September (2004).

DOI: 10.1007/bf03266474

[3] Ulysse, P. Three-dimensional modeling of the friction stir-welding process, International Journal of Machine Tools & Manufacture Vol. 42 (2002), pp.1549-1557.

DOI: 10.1016/s0890-6955(02)00114-1

[4] Russell, M. J. Schercliff, H. R. Analytical modelling of microstructure development in friction stir welding, in 1 st International FSW Symposium, Thousand Oaks, USA, June (1999).

[5] Colegrove, P. 3 Dimensional flow and thermal modeling of the friction stir welding process, in 2 nd International FSW Symposium, Stockholm, Sweden, (2000).

[6] Lienert, T. J. Stellwag, W. L. Lehman, L. R. Heat inputs, peak temperatures and process efficiencies for FSW, in 4 th International FSW Symposium, Utah, USA, May (2003).

[7] Vilaça, P. Quintino, L. dos Santos, J. F. Zettler, R. Sheikhi, S. Quality assessment of friction stir welding joints via an analytical thermal model, iSTIR, Materials Science and Engineering Vol. A445-446 (2007), pp.501-508.

DOI: 10.1016/j.msea.2006.09.091