On FSW Keyhole Removal to Improve Volume Defect Using Pin Less Tool

Friction stir welding (FSW) consists formation of keyhole at the end phase of the process, which is major defect and needs to be removed. In the present investigation, keyhole of dissimilar friction stir welded Al-Mg joint was repaired by novel technique of pin less tool friction stir repairing. Two different pin less tools having different tool diameters were applied to repair keyhole. Visual inspection, macro structural analysis, microstructure features and mechanical properties are assessed in order to check the successful prevail over of keyhole defect. The results revealed that, keyhole of dissimilar friction stir weld of Al-Mg joint was effectively repaired by pin less tool friction stir repairing. Excellent material mixing was obtained in the repaired area of keyhole. Tensile strength was obtained as 159 MPa that was higher than the dissimilar Al-Mg FSW joint.

An Optimized Method for Choosing Friction Stir Welding Parameters

Effect of rotating speed and welding velocity on properties of 6063-3A21 dissimilar Friction Stir weld was experimental studied, results show that too high or too low welding velocity will result in a decrease of the weld strength; effect of rotating speed on weld strength is relatively small. An optimized method for Choosing Friction Stir Welding parameters was proposed, which include three steps, first, fix a rotating speed through experimental analysis; and then find out reasonable ranges of v/w; finally work out the optimized welding speed range.