Experimental Investigations on the Feeding Force and Its Formation Mechanism During Friction Stir Welding of Aluminum Alloy Using a Novel Dynamometer

摘要

A novel dynamometer is proposed to measure the time histories of welding forces including the downward, clamping, and feeding forces during friction stir welding (FSW). The FSW experiments involving the butt joining of aluminum alloy 6061-T6 plates are carried out under the welding parameters including the different rotating speeds (400 to 1600 rpm) and feeding speeds (5 to 80 mm/min) with the welding tool of SKH51 high-speed steel to investigate mainly the effects of the welding parameters on the feeding force and the formation mechanism of the feeding force. Empirical equations of the mean downward force, the mean feeding forces and the mean feed coefficient in terms of rotating speed and the feeding speed are derived. The mean downward force, the mean feeding force and the mean feed coefficient are physically influenced by the interface temperature between the tool and the workpiece material. The feeding is the difference between the friction forces, respectively acted on the advancing side and the retreating side of workpiece. The feeding force is much smaller than the friction force.