Lehrstuhl für Fertigungstechnologie, Universität Erlangen-Nürnberg

Fundamental investigations on the extrusion of metal microparts



Datum: 18.12.2001


Author


Reporter

  • Prof. Dr.-Ing. M. Geiger
  • Prof. Dr.-Ing. M. Kleiner, Universität Dortmund

In the field of electronics, micro mechanics and in micro systems technology (MST) small metallic parts like contact pins or miniature screws are needed in large numbers. For the mass production of such parts metal forming technology offers technological, economical and ecological advantages compared to alternative manufacturing technologies. However, the industrial breakthrough is still missing, mainly due to a lack of adequate machines, tools and process knowledge. The latter arises from the fact that the process knowledge from conventional (macro) forming cannot be transferred to the micro area due to miniaturization effects that occur when scaling down the process. For the present work the extrusion process was chosen, because it could be well suited for the production of small axis-symmetric parts like contact pins. The main focus are miniaturization effects in frictional behavior and their influence on extrusion processes. The influence of specimen size and microstructure on process forces, forming behavior in combined extrusion and hardness distribution in the extruded part are investigated. Additional friction tests and rod extrusion experiments take into account the influence of surface quality, forming speed and lubricant on miniaturization effects. The presented results illustrate that an effective process design can only be accomplished when considering various miniaturization effects. The theoretical background and the practical consequences for extrusion processes have been described in detail. Thus, a fundamental process knowledge has been created which offers a good basis for further investigations.