TWI

Dissimilar lap joints were fabricated between 6022 aluminium alloy and SPCC low carbon steel using friction stir welding (FSW) and the effect of probe tip position on microstructure and mechanical properties was investigated. FSW was performed at a tool rotational speed of 3000 rpm and traverse speed of 25 mm/min, with the probe tip positioned either 0.1 mm above or 0.1 mm beneath the Al/steel interface. Microstructure was observed by optical microscopy, SEM, backscattered electron imaging and TEM. Composition analysis was conducted by electron probe microanalysis and energy dispersive spectroscopy. Mechanical properties were characterised by hardness measurements as well as shear and peel tests. Grain refinement and laminate structure issues are discussed.

7th International Symposium, 20-22 May 2008, 4A: Process/Microstructure 1, Paper 04