TWI

Friction stir spot welding experiments were conducted on dissimilar metal joints between AA5052 aluminium alloy and three kinds of zinc coated steel, and weldability analysis, microstructure observations and mechanical tests were undertaken. The coated steels were prepared by Zn electroplating, Zn-Ni electroplating and Zn hot dipping. The rotating tool incorporated a shoulder with a small conical centre probe and the tool material was diamond-coated WC-Co. The process parameters varied were rotational speed, plunging speed, plunge depth and hold time. Weld interface microstructure was observed by SEM and fracture surfaces were examined by x-ray diffraction and energy dispersive x-ray analysis. Mechanical properties were characterised by tensile shear and cross tensile strength tests.

7th International Symposium, 20-22 May 2008, 2A: Spot 1 (Al-Steel), Paper 03