Lehrstuhl für Fertigungstechnologie, Universität Erlangen-Nürnberg

Forming of complex functional elements on sheet metal (TR73-A2)

Project Status: Active


Objective of subproject A2 is a fundamental analysis for the manufacturing of complex functional parts out of sheet metal using cold forging operations. A special focus is set on short process chains. Within the current second project phase it is investigated, whether it is possible to transfer the existing knowledge on the forming of geometrically identical functional elements on element combinations of different shape and size. However, as the figure below illustrates, a different mold filling can be observed, which is directly related to the choice and placement of the cavities. Hence strategies have been developed and verified in further investigations to encounter this challenge. Using numerical and experimental investigations, the effectiveness of “Tailored Surfaces” and Tailored Blanks has been verified for the targeted control of the material flow.

 A2 2014


Insufficient mold filling in a cold forging process by use of different functional elements

As a result of the typically high contact areas between the workpiece and the tool, the tool loads approach the current limits of conventional tool steels and reinforcement systems. Hence, tool stresses have been analyzed in order to identify the central influencing variables. The investigation shows that the resulting tool stresses are dependent on the geometrical form and their placement. Based on the results, the forming tools have been designed accordingly. Furthermore, in order to improve tool life and reliability, the process forces have to be made controllable by means of a further development of the tool technology. This is achieved by the use of alternative non-circular reinforcements, which enable the targeted adjustment of its properties in order to encounter the asymmetrical tool loads resulting from the forming of non-similar functional elements. Besides this, research is conducted on fatigue strength characterization of high strength tool steels in order to give precise predictions regarding the tolerable tool loads and therefore enable the full use of the potential of the tool steel in question.

This project is supported by the German Research Foundation (DFG) within the scope of the Transregional Collaborative Research Centre on Sheet-Bulk metal forming (SFB/TR 73).


Research Groups



    • Pilz, F.; Merklein, M.:
      Comparison of Extrusion Processes in Sheet-Bulk Metal Forming for Prodcution of Filigree Functional Elements.
      CIRP Journal of Manufacturing Science and Technology, DOI: 10.1016/j.cirpj.2019.05.004 (2019), accepted


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

    • Pilz, F.; Gröbel, D.; Merklein, M.:
      Investigation of Fatigue Strength of Tool Steels in Sheet-Bulk Metal Forming.
      In: The 21st International ESAFORM Conference on Material Forming (Edtr.): AIP Conference Proceedings, doi: 10.1063/1.5035048, 2018, published

    • Pilz, F.; Merklein, M.:
      Numerical Research of Sheet-Bulk Metal Forming Using a Forward and a Lateral Extrusion Process.
      In: ICFG - International Cold Forging Group (Edtr.): Proceedings 51st ICFG Plenary Meeting 2018, Ohio USA, 2018, pp. 221-232


    • Merklein, M.; Lechner, M.; Gröbel, D.; Löffler, M.; Schneider, T.; Schulte, R.; Hildenbrand, P.:
      Innovative approaches for controlling the material flow in sheet-bulk metal forming processes.
      Manufacturing Review 3(2016)2, pp. 1-17

    • Gröbel, D.; Schulte, R.; Hildenbrand, P.; Lechner, M.; Engel, U.; Sieczkarek, P.; Wernicke, S.; Gies, S.; Tekkaya, A.E.; Behrens, B.A.; Hübner, S.; Vucetic, M.; Koch, S.; Merklein, M.:
      Manufacturing of functional elements by sheet-bulk metal forming processes.
      Production Engineering: Research and Development 10(2016)1, pp. 63-80

    • Andreas, K.; Henneberg, J.; Koch, J.; Merklein, M.:
      Local adjustment of surface integrity of forming tools by adaptation of tool making process.
      Procedia CIRP 45(2016), pp. 339-342

    • Löffler, M.; Andreas, K.; Engel, U.; Schulte, R.; Gröbel, D.; Krebs, E.; Freiburg, D.; Biermann, D.; Stangier, D.; Tillmann, W.; Weikert, T.; Wartzack, S.; Tremmel, S.; Lucas, H.; Denkena, B.; Merklein, M.:
      Tribological measures for controlling material flow in sheet-bulk metal forming.
      Production Engineering 10(2016), pp. 459-470


    • Gröbel, D.; Schneider, T.; Merklein, M.:
      Sheet-Bulk Metal Forming.
      In: Tekkaya, A.E.; Homberg, W.; Brosius, A. (Edtrs.): 60 Excellent Inventions in Metal Forming, Springer, 2015, pp. 101-106

    • Gröbel, D.; Hildenbrand, P.; Engel, U.; Merklein, M.:
      Influence of tailored blanks on forming of cold forged functional elements in a sheet bulk metal forming process.
      In: Stahl-Institut VDEh (Edtr.): Proceedings METEC & 2nd ESTAT, 2015, published on CD

    • Löffler, M.; Gröbel, D.; Engel, U.; Andreas, K.; Merklein, M.:
      Analysis of Effectiveness of Locally Adapted Tribological Conditions for Improving Product Quality in Sheet-Bulk Metal Forming.
      Applied Mechanics and Materials 794(2015), pp. 81-88

    • Merklein, M.; Gröbel, D.; Löffler, M.; Schneider, T.; Hildenbrand, P.:
      Sheet-bulk metal forming – forming of functional components from sheet metals.
      In: Y. Qin, T.A. Dean, J. Lin, S.J. Yuan, F. Vollertsen (Edtr.): Proceedings of the 4th International Conference on New Forming Technology, MATEC Web of Conferences, 2015, pp. 01001 1-12


    • Merklein, M.; Schneider, T.; Gröbel, D.; Nürnberger, F.:
      Blechmassivumformung – vom Halbzeug zum Funktionsbauteil.
      In: Behrens, B. A. (Edtr.): 21. Umformtechnisches Kolloquium Hannover, Industrie und Wissenschaft – Gemeinsam die Zukunft gestalten, 2014, pp. 265-280

    • Merklein, M.; Andreas, K.; Gröbel, D.; Hildenbrand, P.; Müller, M.; Noneder, J.; Zimmermann, A.; Schneider, T.; Vierzigmann, U.:
      Potenziale und Grenzen der Simulation in der Fertigungstechnik.
      In: simufact engineering GmbH (Edtr.): Tagungsband 15. RoundTable - Simulating Manufacturing, ISBN: 978-3-9813814-3-6, 2014, pp. 1-38

    • Gröbel, D.; Koch, J.; Vierzigmann, U.; Engel, U.; Merklein, M.:
      Investigations and approaches on material flow of non-uniform arranged cavities in sheet bulk metal forming processes.
      Procedia Engineering 81(2014), pp. 401-406


    • Koch, J.; Merklein, M.:
      Cold forging of closely-tolerated functional components out of blanks – possibilities of the new process class sheet-bulk metal forming.
      In: Ishikawa, T. (Edtr.): Proc. 6th JSTP Int. Seminar Precision Forging, 2013, pp. 109-112

    • Vierzigmann, U.; Schneider, T.; Koch, J.; Gröbel, D.; Merklein, M.; Engel, U.; Hense, R.; Biermann, D.; Krebs, P.; Kersting, P.; Henning, L.; Denkena, B.; Herper, J.; Tillmann, W.:
      Untersuchungen von Tailored Surfaces für die Blechmassivumformung mittels angepasstem Ringstauchversuch.
      In: Merklein, M.; Behrens, B. A., Tekkaya, A. E. (Edtrs.): 2. Workshop Blechmassivumformung, Meisenbach, 2013, pp. 137-162


    • Hetzner, H.; Koch, J.; Tremmel, S.; Wartack, S.; Merklein, M.:
      Improved Sheet Bulk Metal Forming Processes by Local Adjustment of Tribological Properties.
      J. Manufacturing Science and Engineering 133(2012)6, pp. 61011_1-11

    • Vierzigmann, U.; Koch, J.; Merklein, M.; Engel, U.:
      Material Flow in Sheet-Bulk Metal Forming.
      Key Eng. Mater. 504-506 (2012), pp. 1035-1040

    • Merklein, M.; Opel, S.; Schneider, T.; Koch, J.:
      Überblick der Blechmassivumformung.
      Umformtechnik 1(2012)3, pp. 42-43


    • Merklein, M.; Koch, J.; Opel, S.; Schneider, T.:
      Fundamental investigations on the material flow at combined sheet and bulk metal forming processes.
      CIRP Annals - Manufacturing Technology 60(2011)1, pp. 283-286

    • Merklein, M.; Tekkaya, A.E.; Brosius, A.; Opel, S.; Koch, J.:
      Overview on sheet-bulk metal forming processes.
      In: G. Hirt, A.E. Tekkaya (Edtr.): Proceedings ICTP 2011, 2011, pp. 1109-1114

    • Schaper, M.; Lizunkova, Y.; Vucetic, M.; Hetzner, H.; Schneider, T.; Plugge, B.; Koch, J.; Opel, S.:
      Sheet-bulk metal forming a new process for the production of sheet metal parts with functional components.
      Metallurgical and Mining Industry 3(2011)7, pp. 53-58

    • Biermann, D.; Merklein, M.; Engel, U.; Tillmann, W. ; Surmann, T. ; Hense, R.; Herper, J. ; Koch, J.; Krebs, E. ; Vierzigmann, U.:
      Umformwerkzeuge in der Blechmassivumformung.
      In: Merklein, M.; Bach, Fr.-W.; Tekkaya, A. E. (Edtrs.): 1. Workshop Blechmassivumformung, Meisenbach, 2011, pp. 119-138


    • Merklein, M.; Koch, J.; Schneider, T.; Opel, S.; Vierzigmann, U.:
      Manufacturing of Complex Functional Components with Variants by Using a new Metal Forming Process – Sheet-Bulk Metal Forming.
      International Journal of Material Forming 3 (2010), pp. 347-350

    Letztes Update: 11.07.2018