Advances in friction stir welding by separate control of shoulder and probe

Abstract

Friction stir welding (FSW) has developed into a reliable and increasing used industrial joining technology. Various tool configurations can be used for FSW, each of which has advantages and challenges. State-of-the-art FSW employs various tool configurations, including the conventional, the stationary shoulder, and the dual-rotational configuration which is characterized by separate control of shoulder and probe. In this study, an innovative method to combine various tool configurations was developed by a novel FSW spindle stack construction. With an additional servomotor, existing FSW systems can be extended by separate control of shoulder and probe so that varying rotational speeds and rotational directions can be set. This allows enhanced possibilities (a) to adjust frictional heat generation and (b) to apply several tool configurations. The main advantages of this enhanced type of FSW are demonstrated in three ways: increased weld penetration depth, reduction of undesirable machine vibrations, and the combination of varying tool configurations such as stationary shoulder and conventional FSW. The investigations were carried out with 2-mm EN AA 5754 H22 sheets and performed on a robotized FSW setup.

Impact of the tool shoulder diameter to pin diameter ratio and welding speed on the performance of friction sir-welded AA7075-T651 Al alloy butt joints

“…On the other hand, considerable heat input, mechanical preparation, and severe occupational safety measures are necessary for TIG and MIG technologies [5]. Shoulder diameter (SD) and welding travel speed (TS), along with other parameters like rotation speed (Rs), tilt angle, and downward force, are also important to control the heat input for the welding material [6][7][8][9][10]. A review by Vaidyanathan et al [11] on the impact of the Shoulder Diameter to pin diameter (PD: SD) ratio on the joint strength of aluminum alloys reported that it compares one of the important parameters that govern tensile strength.…”