Design an processing with a compact, adaptable high-speed FSW spindle stack with direction- and rotational speed-independent control of shoulder and probe.
By Michael Grätzel (Technische Universität Ilmenau), Konstantin Schick-witte (Technische Universität Ilmenau), Felix Sieber (Technische Universität Ilmenau), Jean Pierre Bergmann (Technische Universität Ilmenau)

Since 1991, continuous advancements of FSW were carried out, especially in fields like modelling, tool design, tool-material interaction and tool concepts as well as their effects on the mechanical weld seam properties of the weld. Concerning the tool concepts, conventional FSW, stationary shoulder and dual rotation FSW were usually investigated separately so far. Herewith, an adaptable spindle stack is presented, which allows the combination of the three mentioned tool concepts at once, except the Bobbin tool, up to 8000 rpm rotary speed. The compact dimensions of the setup as well as the control of rotational speed and direction of shoulder and probe allow for precise heat input and hence an improved joining of similar and dissimilar materials. Furthermore, it is demonstrated how the speed and direction of rotation influence the joining temperature as well as the metallurgical and mechanical strength properties of the joints.