Ultraschallüberlagertes Umformen und Verstemmen von Stahlwerkstoffen

Description

The staking process is characterized by high process forces, which severely limit the use of the joining process. The superimposing of mechanical joining and forming processes with ultrasonics demonstrate great potential in reducing process forces, which could expand the process limits of the staking process. However, a lack of process knowledge has so far prevented the industrial application of ultrasonic superimposed processes. The central purpose of this thesis is a basic process understanding for the ultrasonic superimposed staking process on the high-alloy stainless steel and the identification of force-reducing mechanisms of the vibration superimposition. In the experiment, the superimposed ultrasonics led to a reduction in the process force up to 59 % and still having a comparable joint strength. Dynamic influences via the superposition principle and tribological influences due to reduced surface friction could be proven to be the decisive mechanisms for the force reduction. In addition, the slight wobbling movement of the forming punch ensures an additional reduction in the process force. The reduced staking force during establishing the joint connection in combination with the comparable resilience offers the considerable potential of expanding the process limits.