TWI

Based on a dynamical control-low stress no distortion (DC-LSND) methodology, an array jet impingement heat sink apparatus was designed to facilitate reductions of residual stress and distortion in friction stir welding (FSW), and test results were obtained for thin-walled specimens of 5A06-O and 6082-T6 aluminium alloys. Experiments were conducted on sheet specimens (thickness 3 mm). Aspects investigated included measurement of FSW thermal cycle, post weld macro distortion, residual plastic strain and stress, assessment of hydrogen content, and mechanical properties of welded joints (evaluated by tensile and bending tests). The results are discussed in relation to the functioning of the array heat sink, control of distortion and residual stress in the workpiece, and the performance of the FSW joint under dynamic cooling. Comparisons are made with conventional FSW.

7th International Symposium, 20-22 May 2008, 3A: Process/Control 1, Paper 02