A Comparative Study of Tool-Pin Profile on Process Response of Friction Stir Welding of AA6082-T6 Aluminium Alloy
This paper presents research work conducted to experimentally establish the process response of two diverse shaped tool-pin profiles for friction stir welding (FSW) AA6082-T6 aluminium. The dwell time was optimised by plunging each tool-pin into a plate sample until the spindle torque stabilised thus ensuring sufficient plasticised material in contact with tool shoulder and the tool-pins. The welds were conducted by employing the optimised dwell time, which in turn revealed a minimised process response time and distance to reach weld stability with respect to (1) the force exerted on the tool-pin in the welding direction, Fx , and (2) the spindle torque, T, during the welding process. Both Fx and T stabilised well within the set (pre-determined) ramp-up distance of 20 mm, indicating that the effective (useful) weld length is maximised. The macrographs also revealed good dynamic material flow within the nugget zone regions and more evident in the nugget zone of the flared tool.