Lehrstuhl für Fertigungstechnologie, Universität Erlangen-Nürnberg

Fundamentals on the miniaturization of sheet metal working processes



Datum: 09.06.1998


Author


Reporter

  • Prof. Dr.-Ing.Dr.h.c. M.Geiger
  • Prof. Dr.Ing. D.Schmoeckel, Darmstadt

The miniaturization of sheet metal working processes follows today's industrial requirements of weight minimization and a large design flexibility in the mass production of, particularly, consumer electronics. By entering the micro field, the subject of miniaturization raises many new questions which are connected first and foremost with an obvious change in the relative meaning of the microstructure and the surface topography of the work material. This thesis deals with the consequences of miniaturization for the mechanical behavior of sheet metal in general as well as with process specific effects of miniaturization. The general part of the investigations refers to results that were obtained in tensile testing. It concerns the aspects of the flow curve, anisotropy and ductility. Process specific effects of miniaturization were assessed in bending and shearing experiments and concern aspects like the tool load and the working accuracy. The choice of both the processes and the work materials (CuNi18Zn20 and CuZn15, thicknesses between 0.1 and 1.0 mm) orientated towards the field of electronics production. All stress and strain parameters in tensile testing are shown to be significantly influenced by miniaturization. They must be considered to be increasingly affected by the specimen geometry as well. In bending and shearing more particular deformation conditions seem to predominate the course of the process. Most characteristic appearances of miniaturization are the very inhomogenuous material behavior and the increase in the deformation resistance.