Intermetallic layers in temperature controlled Friction Stir Welding of dissimilar Al-Cu-joints

20th Chemnitz Seminar on Materials Engineering - 20. Werkstofftechnisches Kolloquium

Marstatt, R.^1 ; Krutzlinger, M.^2 ; Luderschmid, J.^1 ; Constanzi, G.^2 ; Mueller, J.F.J.^1 ; Haider, F.^1 ; Zaeh, M.F.^2

Department of Experimental Physics 1, University of Augsburg, Universitaetsstr. 1, Augsburg

86159, Germany^1

Institute for Machine Tools and Industrial Management (Iwb), Technical University of Munich, Boltzmannstr. 15, Garching

85748, Germany^2

关键词: Electrical applications;    Friction stir welding(FSW);    Growth of intermetallics;    Intermetallic layer;    Intermetallic phasis;    Joining mechanisms;    Solidus temperature;    Welding temperatures;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/373/1/012017/pdf
DOI  :  10.1088/1757-899X/373/1/012017

来源: IOP

【 摘 要 】

Friction Stir Welding (FSW) can be performed to join dissimilar metal combinations like aluminium and copper, which is of high interest in modern production of electrical applications. The amount of intermetallic phases in the weld seam is significantly reduced compared to traditional fusion welding technologies. Because the solidus temperature is typically not reached during FSW, the growth of intermetallic phases is impeded and the intermetallic layer thicknesses typically remains on the scale of a few hundred nanometres. These layers provide a substance-to-substance bond, which is the main joining mechanism. Latest research confirms that the layer formation is most likely driven by the heat input during processing. Hence, the welding temperature is the key to achieve high quality joints. In this study, aluminium and copper sheets were welded in lap joint configuration using temperature-controlled FSW. An advanced in-tool measurement set-up was used to determine precise temperature data. Scanning electron microscopy (SEM) was used to analyse metallurgical aspects (e.g. structure and composition of the intermetallic phases) of the joints. The results show a correlation between the welding temperature and the thickness of the intermetallic layer and its structure. The temperature control significantly improved the correlation compared to previous studies. This leads to an enhanced understanding of the dominating joining mechanisms.