Lehrstuhl für Fertigungstechnologie, Universität Erlangen-Nürnberg

Qualification of a Process Chain for Laser Sintering of Metal Parts



Datum: 23.03.2005


Author


Reporter

  • Prof. Dr.-Ing. Dr.-Ing. E.h. mult. Dr.h.c. M. Geiger
  • Prof. Dr.-Ing. W. Schweiger

Laser sintering of metal parts is a quite new process for the production of metallic parts. The main application field of this process is Rapid Prototyping, Rapid Tooling and Rapid Manufacturing. However, a detailed knowledge on the process induced temperature- and stress fields, and the effects of the process parameter on these, has been missing, due to the short history of this manufacturing process. During the laser sintering process cracks can occur in the part due to internal stresses, and internal stresses can cause a deformation of the work piece One objective of the presented work was to stabilise the process of laser sintering through a better understanding of the effect of delamination, and to show the effects of the process parameters on this phenomenon. To achieve this, a FE-based process model was developed, verified and applied. This leads to strategies for reducing the effect of delamination. Results showed furthermore, that warpage is mainly dependent on the induced energy. A two step processing with an additional infiltration is therefore preferable in means of part quality and process stability. A process chain was developed with a fast laser sintering process and a qualified infiltration process. The resulting part quality with this process chain equals conventional laser sintered parts in means of mechanical properties, is faster than the conventional one step laser sintering and more economical.