A Review of Force Control Techniques in Friction Stir Process

This paper reviews current force control techniques in friction stir welding for aluminium alloys. In the context of friction stir process, travel force control, axial force control and torque control are studied in accordance to the control technique, tool geometry and process parameters such as travel speed, tool rotational speed and tilt angle that significantly affect the welding process. Thus, this study highlights the potentials and shortcomings of this control strategy which eventually leads to better performance in friction stir process. It provides insights on ways to improve the quality of welding in terms of microstructure and consistency of weldment formation as well as the elimination of wormhole generation.