Manufacturing of complex functional graded workpieceswith the friction -spinning process

In recent years, the demands on lightweight constructions with respect to their functional qualities and their potential to save resources by reducing weight have increased significantly. Tailor-made components with functionally graded properties manufactured by a novel so-called friction-spinning process meet these demands very well. This new process combines elements from metal spinning and friction welding to a new thermo-mechanical process for the manufacturing of complex hollow parts made of tubes, profiles, or sheet metals. In the process a workpiece, for example a tube, is set into rotation in a conventional spinning machine while a pressure or friction plate works in axial direction on the tube end. In the contact zone the temperature increases strongly by friction. A further movement of the friction plate and optional supplemental forming tools allow the deformation of the warm material and the generation of the desired geometry. With this new process it is possible to extend existing forming limits and to produce complex geometries like flanges or hollow structures, which are not producible by conventional processes. Furthermore, it is possible to influence the workpiece properties or grain structure locally in a defined way. It is possible to realize intense grain refinement in the deformation zone during this thermo-mechanical forming operation.