Study of Thermal and Heat Transfer Phenomenon in Friction Stir Welding of Aluminum Alloy 6061-T6 Thick Plates

In the friction stir welding (FSW) process, heat is generated by friction between the interfaces between the tool and the workpiece. The amount of heat conducted into the workpiece determines the quality of the weld. In this paper, 37.6 mm (1.48 inch) thick plates made of aluminum alloy 6061-T6 were welded using the FSW process. We report (a) welding parameters such as tool RPM, welding speeds, (b) power and heat input to the welding process, (c) a complete temperature history from 27 thermocouples. Data are reported for one weld with a full-length pin and two welds with a short pin. In conjunction with the measurement, finite element analyses were also performed to study (1) the heat inputs from the tool shoulder as well as from the probe pin, and (2) temperature distribution and history in the workpiece. The analysis results are also compared with the measured data.