Lehrstuhl für Fertigungstechnologie, Universität Erlangen-Nürnberg

Bulk microforming of small metal components from strip

Project Status: finished


A high production rate of small metallic parts can be realized by bulk microforming (BMF) processes. Currently, mass production is limited to single-stage forming processes due to lack of system technology. For the realization of more complex geometries multistage processes are required. Thereby, new challenges arise regarding the handling between the forming stages. BMF from sheet metal strip represents a possible solution to meet these challenges by eliminating the complex handling of the microparts between the press stages. The sheet metal strip serves here simultaneously as a semi-finished product and as a handling tool. The separation of the microparts from the sheet metal strip takes place in the final process stage. The lack of lateral boundary of the die results in a material flow in the sheet metal plane during forming. That affects the process accuracy and the achievable forming of the components negatively. Due to the changed boundary conditions and size effects, the process knowledge from the conventional macro- and microforming cannot be transferred directly for BMF from sheet metal strip.

The aim of this project is the development of a basic understanding of multistage BMF processes from sheet metal strip. In this context, a multi-stage extrusion process from sheet metal strip has to be investigated numerically and experimentally. The focus of the investigations lies on the possibilities for material accumulation by full forward extrusion in the first forming stage. The objective is a maximization of the component forming. For this purpose, the significant influencing factors on the forming will be identified and methods to control the material flow will be analyzed. For derivation of universal design guidelines, the influence of material, process and size effects are taken into account.

Research Groups



    • Kraus, M.; Hufnagel, T.; Merklein, M.:
      Accuracy of conventional FE-Models in Bulk-Forming of Micropins from Sheet Metal.
      J. Micro Nano-Manuf, doi: 10.1115/1.4042965 7(2019)1, published

    • Kraus, M.; Frey, P.; Kleffel, T.; Drummer, D.; Merklein, M.:
      Mechanical Joining Without Auxiliary Element by Cold Formed Pins for Multi-Material-Systems.
      In: AIP Conference Proceedings 2113, 050006 (Edtr.): Proceedings of the 22nd International ESAFORM Conference on Material Forming, DOI: 10.1063/1.5112570, 2019, pp. 1-6


    • Degner, J.; Herrmann, J.; Junker, F.; Berendt, E.; Merklein, M.:
      Leichtbauwerkstoffe für den modernen Automobilbau.
      Zeitschrift Konstruktion 3(2018), pp. 50-54

    • Kraus, M.; Hufnagel, T.; Merklein, M.:
      Verification of the Accuracy of FE-Models in Bulk-Forming of Micropins from Sheet Metal.
      In: Joško Valentinčič, Martin Byung-Guk Jun, Kuniaki Dohda, and Stefan Dimov (Edtrs.): WCMNM 2018 World Congress on Micro and Nano Manufacturing , 2018, pp. 185-188

    Letztes Update: 03.07.2018