The aim of the project lies in the adjustment of both material flow and heat input in friction stir welding, in order to improve the fatigue behavior and reduce the related forces and loads on clamping devices. This is to be achieved by decoupling the pin and shoulder movement during welding treatment. The underlying approach is that the heat input can be influenced by distinct settings of rotational speed and direction between the pin and shoulder, thus significantly affecting the material flow. Furthermore, the grain size and its distribution are witnessed to vary in the stirred and thermo-mechanically affected zone. A uniform grain distribution is to be assumed in special cases, for the existence of different conditions for crack initiation and fatigue failure.

Duration: 2017 until 2019