Abstract: A sonotrode for friction welding of at least two joining parts, which are at least partly made of weldable material, in particular plastic material. The sonotrode comprises a basic body with a first axial end and an opposite second axial end, with the basic body having a central longitudinal axis extending through the first and the second axial end and along which the sonotrode is movable in operation. Furthermore, adjacent to the second axial end, a work surface is provided at the basic body laterally with respect to the central longitudinal axis, which in operation is contactable to one of the joining parts, so that joining energy is laterally introducible into a joining zone between the joining parts. The work surface encompasses the basic body circumferentially, preferably without interruption, and comprises a structure that is adapted to a shape of at least one of the joining parts.

Abstract: A composite camshaft is made by simultaneous through transmissive laser welding cams, bearing assemblies and load introduction parts to a fiber composite support tube.