TWI

FSSW has been performed in two different automotive 1.5 mm-thick aluminium alloys– AA5754-H22 and AA6082-T6 in similar and dissimilar combination using different joining parameters (e.g. plunge rate, rotational speed and dwell time). Plunge depth has been held constant at approximately 2.3 mm (0.2 mm of shoulder plunge depth and 2.1 mm of pin plunge depth) corresponding to approximately 75% of the combined thickness (3 mm) of the overlapping sheets. FSSW connections have been accomplished using same tool geometry - cylindrical 3 flute pin (5 mm diameter and 2.1 mm length) and flat shoulder (15 mm diameter). Mechanical behaviour has been investigated in terms of cross-tension and tensile shear testing. The fracture surface of the FSSW connections has been investigated using a stereoscope. Three different failure modes have been observed in tensile shear specimens: shear fracture through the bonded region; non-circumferential nugget pull-out as well as circumferential nugget pull-out.

8th International Symposium, 18-20 May 2010, Poster Session, Paper 05