Friction Stir Welding of 6061 al alloy by floating bobbin tool

The bobbin tool is a new design of the friction stir welding tool that provides the opportunity of the simultaneous double sided welding. The present research aims to design and manufacture a floating bobbin tool; the capability of which is examined through welding aluminum alloy 6061. The results indicated that the high quality and defect-free butt welds can be produced via this tool. Moreover, the strength of the welds is similar to the strength of welded samples done by the conventional friction stir welding method. Regarding the quality and strength, the obtained samples were investigated by mechanical tests including tensile strength test and hardness test. Obtaining 60.7% joint efficiency is indicative of success in the friction stir welding process; and, thus the efficiency of the designed tool. Besides, the second major characteristic of welding is the hardness, which is due to the dissolution of sediments, is decreased in the stirred area. This finding is confirmed by the behavior reported by the other investigators in the literature.