摩擦攪拌点接合によるアルミニウム合金継手の機械的性質におよぼすプローブ形状の影響

抄録

Friction stir spot welding of dissimilar aluminium alloys using the three-flat tool is carried out in order to investigate the effects of probe geometry on mechanical properties. The failure loads in A5754/A6111 lap joints made using a three-flat 0.5 mm no-thread tool were always higher than the joints made using a three-flat 0.5 mm threaded tool. Material flows due to the shear deformations were observed in the stir zone of A5754/A6111 and A5052/A6061 lap joints made using the three-flat tools. In addition, the bonded and stir zone widths in A5052/A6061 lap joints made using a three-flat 0.7 mm no-thread tool (in which the arc lengths of the triangular vertex region in the cross-section of probe were shortened) were always smaller than the joints made using a three-flat 0.5 mm no-thread tool. Therefore, it is suggested that there are pressures in a horizontal direction which are produced by the triangular vertex regions on the probe.