In the aircraft industry, joining technologies get more and more important, because they represent a high expense factor when components have to be assembled. Riveting is the current state-of-the-art joining method due to its very safe and robust application. However it is a time and weight consuming technology as it requires overlapping sections that have to be drilled in order to place the rivets in up to three rows. Thus, the aircraft industry currently evaluates several welding technologies to reduce production and maintenance cost as well as the weight of aircrafts for longer range and higher efficiency. Friction Stir Welding (FSW) represents an innovative joining technology that allows the welding of all aluminium alloys of interest with excellent seam properties and with thicknesses from 0.3 mm up to 50 mm and more. The substitution of automated riveting by FSW can lead to a significant reduction of process time and a cost reduction of up to 20 %. In contrast to conventional welding techniques FSW requires high process forces, which act on the joining partners and the actuator. Thus, usually special and individual machines have been designed and built, leading to significant investment costs and the risk of missing reliability after delivery caused by the low production rate and the lack of experience with the individual machine type.
For Friction Stir Welding of thin sections up to 5 mm modern industrial robots are also suited and represent an alternative machine concept to specially designed FSW machines. They feature an enormous flexibility combined with low invest costs compared to special machines. This paper presents the latest results of the project “RoboFSW”, realised by Airbus Deutschland GmbH, Bremen, EADS Innovation Works Germany, Munich, KUKA Roboter GmbH, Augsburg and the Institute for Machine Tools and Industrial Management (iwb) of the Technische Universität München. It shows the use of a KUKA KR500 high payload robot in order to produce 3-dimensional welds on aerospace aluminium components.
