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C1 - Friction Law

Constitutive Friction Law for the Description and Optimization of Tailored Surfaces

Project Status: Active

Last Update: 24.09.2020


The forming of functional elements by means of sheet-bulk metal forming causes a partially uncontrolled material flow due to strain induced strength gradients. This results in a reduced geometrical accuracy of parts. Within the scope of the project, tailored friction systems for a material flow control by local adaptation of friction are investigated. As a basis for this, a numerical half-space model was developed which enables the analysis of the contact between the tool and workpiece under varying tribological loads. Numerical analyses of sheet-bulk metal forming processes are conducted in order to determine the requirements for tailored friction systems with regard to friction factor gradients, partitioning and tribological loads. Based on this, tool- and workpiece-sided measures are investigated to evaluate their suitability for a local adaptation of friction. Numerical methods are applied to derive the functional relationships of the modifications. The functional stability of tool-sided measures is additionally investigated on a newly developed wear test rig. The analysis of surfaces, friction and adequate process parameters allows to derive the functional correlations between topography, wear and functional stability. Finally, suitable surface modifications are used to verify the findings regarding the material flow control in the forming processes of the Collaborative Research Centre. The effectiveness of measures to improve the process result and extend the process boundaries in sheet-bulk metal forming processes will be demonstrated.

Methodik eng


Working Groups



    • Pilz, F.; Henneberg, J.; Merklein, M.: Extension of the forming limits of extrusion processes in sheet-bulk metal forming for production of minute functional elements. In: Manufacturing Review, 7(2020), pp. 1-12
    • Henneberg, J.; Beyer, F.; Willner, K.; Merklein, M.: Konstitutives Reibgesetz zur Beschreibung und Optimierung von Tailored Surfaces. In: 23. Umformtechnisches Kolloquium Hannover (Edt.): Aktuelle Entwicklungen im Bereich der Umformtechnik, (2020), accepted
    • Henneberg, J.; Merklein, M.: Investigation on extrusion processes in sheet-bulk metal forming from coil. In: CIRP Journal of Manufacturing Science and Technology, (2020), accepted
    • Henneberg, J.; Merklein, M.: Measures for controlling the material flow when extruding sheet-bulk metal forming parts from coil. In: Manufacturing Review, (2020), accepted


    • Löffler, M.; Schulte, R.; Freiburg, D.; Biermann, D.; Stangier, D.; Tillmann, W.; Merklein, M.: Control of the Material flow in sheet-bulk metal forming using modifications of the tool surface. In: International Journal of Material Forming, 12(2019), pp. 17-26
    • Freiburg, D.; Aßmuth, R.; Garcia Carballo, R.; Biermann, D.; Henneberg, J.; Merklein, M.: Adaption of tool surface for sheet-bulk metal forming by means of pressurized air wet abrasive jet machining. In: Production Enginieering, 13(2019), pp. 71-77
    • Merklein, M.; Gröbel, D.; Löffler, M.; Henneberg, J.: Investigation on blasted tool surfaces as a measure for material flow control in sheet-bulk metal forming. In: Manufacturing Review, 6(2019), pp. 1-9
    • Henneberg, J.; Lucas, H.; Denkena, B.; Merklein, M.: Investigation on the Tribological Behavior of Tool-sided Tailored Surfaces for Controlling the Material Flow in Sheet-Bulk Metal Forming. In: AIP Conference Proceedings 2113 (Edt.): Proceedings of the 22nd International ESAFORM Conference on Material Forming, (2019), pp. 1-6


    • Löffler, M.; Engel, U.; Willner, K.; Beyer, F.; Merklein, M.: Investigation of the tribolgocal behaviour of microstructures for controlling the material flow in sheet-bulk metal forming. In: CIRP Journal of Manufacturing Science and Technology, 22(2018), pp. 66-75
    • Merklein, M.; Löffler, M.; Gröbel, D.; Henneberg, J.: Material flow control in sheet-bulk metal forming processes using blasted tool surfaces. In: Qin, Y.; Dean, T.A.; Lin, J.; Yuan, S. J.; Vollertsen, F (Edt.): MATEC Web of Conferences, (2018), published
    • Löffler, M.: Steuerung von Blechmassivumformprozessen durch maßgeschneiderte tribologische Systeme. In: Franke, J.; Hanenkamp, N.; Merklein, M.; Schmidt, M.; Wartzack, S. (Edt.): FAU Studien aus dem Maschinenbau, 308(2018), Erlangen: FAU University Press, pp. 1-166
    • Löffler, M.: Steuerung von Blechmassivumformprozessen durch maßgeschneiderte tribologische Systeme, Dissertation(2018), published


    • Löffler, M.; Engel, U.; Andreas, K.; Merklein, M.: Identification of tribological mechanisms of shot peened steel surfaces for an application in sheet-bulk metal forming. In: Levesque, M. (Edt.): Proceedings of the 13th International Conference on Shot Peening, (2017), pp. 67-72
    • Freiburg, D.; Löffler, M.; Merklein, M.; Biermann, D.: Surface structuring of forming tool surfaces by high feed milling. In: WGP Jahreskongress, (2017), published
    • Merklein, M.; Andreas, K.; Kraus, M.; Löffler, M.; Pilz, F.: Development and launching of an application-oriented test rig for wear investigations in sheet-bulk metal forming. In: THE"A" Coatings, (2017), pp. 31-40



      • 27.03.2019: Henneberg, J.: Smart Tool, Stuttgart, GCFG
      • 09.05.2019: Henneberg, J.: Untersuchung des tribologischen Einsatzverhaltens werkzeugseitiger Oberflächenmodifikationen für eine Stoffflusssteuerung in der Blechmassivumformung, Vitoria Gasteiz, ESAFORM


      • 20.09.2018: Henneberg, J.: Abrasivgestrahlte Werkzeugoberflächen zur Stoffflusssteuerung in der Blechmassivumformung, Bremen, ICNFT