Effect of temperature field and pressure force on the inhomogeneity of 5754-H22 and 6082-T6 FSW joints

摘要

The Friction Stir Welding (FSW) differs from the conventional welding process inter alia that the joint properties are not symmetric to the axis of joint line. Basically, it follows from the principle of the method because a rotary tool is used for welding. This asymmetry is due to the created temperature field during welding, and the pressure force distribution along the thickness, so the investigation of these effects is important for creating good quality welds. Experiments were performed on FSW joints made of non-heat treatable (5754-H22) and heat treatable (6082-T6) aluminium alloys. The selection of these alloys was motivated from their different reactions to FSW, e.g. as manifested by their post weld microstructures. A special FSW tool was developed for the experiments in order to achieve the lowest inhomogeneity. Dynamic recrystallization and dynamic recovery maybe can occur during welding so these were investigated by a Gleeble material simulating system. During the experiments the grain sizes and grain shapes were investigated.