Friction stir welding

© Fraunhofer IPA

Friction stir welding is a relatively new welding technology which is classified as a pressure welding process. Today, this welding technique is almost exclusively used in industry for joining materials made from metal. Excellent welding results are achieved and the method can be applied in all areas of industry. Therefore, despite its relatively short development time, the technology has been widely accepted by industry for joining metallic materials.

Up till now, this technique has hardly been used in Germany for welding fiber-reinforced plastics. However, this contradicts the enormous potential of the technique. The advantage of this method is that reinforcing fibers can be stirred into the joining area during the welding process. Compared to joins generated using conventional welding and bonding techniques, these joins are much stronger because the reinforcing fibers vastly improve their mechanical properties.

In order to be able to carry out fundamental tests on a wide range of materials (using different reinforcing fibers, varying the volume content of fibers and/or the matrix material), we have designed a flexible test facility. The Department of Lightweight Construction Technologies also has the necessary testing equipment to evaluate welding results. This enables us to address new issues and applications swiftly. To weld complex three-dimensional workpieces, we have an end-effector for friction stir welding. Designed for use with an industrial robot, it can also be implemented in conjunction with portal systems. A further focus of research projects is on mobile welding applications with hand-held devices. Project results are then transferred to develop industrial processes.