Investigation of current pulse and vibration superimposed embossing processes

• Applicants: Dr.-Ing. Sven Hübner; Dr.-Ing. Florian Nürnberger
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing ; Mechanical Properties of Metallic Materials and their Microstructural Origins
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 556377329

Sheet metal materials can reach their ultimate strength quickly, especially in multi-stage cold forming processes. This limits the forming production of components with demanding geometries. For components requiring a high degree of forming, multi-stage cold forming processes are difficult or even impossible to realize due to strain hardening. The project focuses on the development of a novel methodology for superimposing electrical impulses and mechanical vibrations on a forming process (stamping). In previous projects, the influence of electrical pulses of high current densities on the microstructural and mechanical properties of multicrystalline magnesium alloys was investigated. The yield stress of the magnesium material used there could be considerably reduced, which was explained by the onset of gliding processes that promote the formation of twins. In addition, in this project a new vibration device, which was developed within the SFB/TR73, shall enable a vibration superposition of the forming process. This reduces friction and improves the flow behavior of the material. By the combined application of impulse treatment and vibration superimposition, a process strategy is being developed that should lead to a reduction in plastic work and a better surface quality. In the project, the influences of the two process modifications on the forming of a corrosion-resistant chromium-nickel steel are first considered separately. This is followed by an investigation of the superposition of the two variants to determine the best possible process parameter combinations. The experiments are accompanied by in-depth microstructure characterizations to identify the mechanisms involved. As demonstrator geometry, a finned structure is chosen, as it is used in industry for fine structures in cooling applications.

• DFG Programme: Research Grants