TWI

Thermodynamic modelling and experimental measurements were employed to investigate the influence of intermetallic compound formation on the shear strength of dissimilar joints between an aluminium alloy and ultra-high strength steel fabricated by friction stir welding. The materials studied were AA 5754 alloy (Al, 2.88%Mg) and hot dip galvanised DP 800 dual phase steel (0.16%C, 1.9%Mn, 0.5%Cr, 0.02%Al). Welding experiments were performed at a tool rotational speed of 1000-3500 rpm, travel speed of 60 mm/min and tilt angle of 2 deg. Cross-sectional microstructures, fracture surfaces and intermetallic compound phase formation were observed by optical microscopy, SEM and energy dispersive spectroscopy. Mechanical testing was conducted in an Instron 4505 testing machine and extensometers were used to measure strain. Thermodynamic calculations were undertaken to study stable phases in the Al/Fe system.

10th International Symposium, 20-22 May 2014, Session 2B: Dissimilar I, Paper 04