Lehrstuhl für Fertigungstechnologie, Universität Erlangen-Nürnberg

Warm Forming of high strength steel using Granular Material as a hydroforming medium

Project Status: finished


Small ceramic spheres with diameters smaller than 1 mm can be used as medium for hydroforming processes at elevated temperatures. Based on results of the previous project stage single spheres, the deviation of mechanical properties and the influence on the behaviour of the continuum are investigated in detail. The description of the resulting properties with an increasing amount of broken spheres and by mixing with dry lubes, which are used to reduce the fricion between blank and tool components at elevated temperatures are also in the point of interest. Addionally the gaind data is used to improve the quality of prediction of the numerical simulation.

Numerical simulation of stress state inside a ceramic sphere (left);
Hertzian contact stess for failure of ceramic spheres in dependency of the diameter (right)

Research Groups



    • Rosenschon, M.; Suttner, S.; Merklein, M.:
      Evaluation of kinematic hardening models for multiple stress reversals under continuous cyclic shearing and multi - step bending.
      In: (Edtr.): LS-DYNA Forum 2015, published online, 2015, published online


    • Grüner, M.; Merklein, M.:
      Determination of friction coefficients in deep drawing by modification of Siebel's formula for calculation of ideal drawing force.
      Prod. Eng. Res. Devel. 8(2014)5, pp. 577-584

    • Grüner, M.; Gnibl, T.; Merklein, M.:
      Blank hydroforming using granular material as medium - investigations on leakage.
      Procedia Engineering 81(2014), pp. 1035-1042


    • Merklein, M.; Grüner, M.; Rösel, S.:
      Enhancing Process Limits of Blank Hydroforming.
      In: Institut für Umformtechnik (IFU) Universität Stuttgart (Edtrs.): Internationale Konferenz „Hydroumformung von Blechen, Rohren und Profilen“, MAT INFO Werkstoff-Informationsgesellschaft mbH, 2012, pp. 61-80


    • Grüner, M.; Merklein, M.:
      Consideration of elastic tool deformation in numerical simulation of hydrofroming with granular material used as a medium.
      Key Engineering Materials 473(2011), pp. 707-714

    • Grüner, M.; Merklein, M.:
      Influences on the Molding in Hydroforming Using Granular Material as a Medium.
      In: Chung, K.; Han, H. N.; Huh, H. Barlat, F.; Lee, M.-G. (Edtrs.): AIP Conference Proceedings Volume 1383 - The 8th International Conference and Workshop on Numerical Simulation of 3D Sheet Metal Forming Processes (NUMISHEET 2011), American Institute of Physics, 2011, pp. 645-652


    • Grüner, M.; Merklein, M.:
      Numerical Simulation of Hydroforming at Elevated Temperatures with Granular Material Used as Medium Compared to the Real Part Geometry.
      Int J Mater Form 3(2010)1, pp. 279-282

    • Grüner, M.; Merklein, M.:
      Comparison of numerical simulation and measurement of shear test and uniaxial compression test to verify material model for granular material used as medium for hydroforming.
      In: Warsaw University of Technology, Faculty of Production Engineering 2010 (Edtr.): Proc. 5th International Conference on Advances in Production Engineering, Publishing and Printing House of the Institute for Suitainable Technologies, 2010, pp. 418-426


    • Grüner, M.; Merklein, M.:
      Mechanical Behaviour of Ceramic Beads Used as Medium for Hydroforming at Elevated Temperatures.
      Key Engineering Materials (2009)410-411, pp. 61-68

    • Grüner, M.; Merklein, M.:
      Mechanical Behaviour of Ceramic Beads Used as Medium for Hydroforming at Elevated Temperatures.
      In: Shirvani, B.; Clarke, R.; Duflou, J.; Merklein, M.; Micari, F.; Griffiths, J. (Edtrs.): Proc. 13th Int. Conf. on Sheet Metal (SheMet 2009), Trans Tech Publications, 2009, pp. 61-68

    Letztes Update: 17.03.2014