Friction stir welding

Rotational friction welding is a highly specialised form of friction welding, which is characterised by a rotating movement, similar to the movement of a workpiece on a lathe. In contrast to other forms of friction welding, in which the movement can be linear or oscillating, rotational friction welding involves continuous rotation of the components to be joined. This rotation is essential for the welding process and requires that the shape and geometry of the components permit this rotational movement.

Typically, rotational friction welding uses components that have a cylindrical or rotationally symmetrical shape, as this facilitates rotation and enables a uniform joint. A good example of this is the welding of a pipe section to a pipe bend. The cylindrical shapes of the pipes allow smooth rotation during the welding process.

This joining method offers various advantages, including high welding quality and integrity as well as efficient energy utilisation. The rotating movement heats the components to be joined, causing the material to become plastic and creating a strong joint. In addition, the rotational movement enables a uniform distribution of heat and thereby reduces the risk of stresses or deformation in the workpiece.