Servicenavigation

Project Details

Back

Projekt Print View

SFB 747:  Micro Cold Forming - Processes, Characterisation, Optimisation

Subject Area Materials Science and Engineering
Computer Science, Systems and Electrical Engineering
Mechanical and Industrial Engineering
Mathematics
Term from 2007 to 2018
Project identifier Deutsche Forschungsgemeinschaft (DFG) - Project number 26068470
 
Final Report Year 2019

Final Report Abstract

The central concern of the Collaborative Research Center "Micro Cold Forming" (SFB 747) of the University of Bremen is the provision of processes and methods for the metal forming of metallic microcomponents. Here lot sizes over 1 million pieces are adressed. The developed processes and methods take into account the special requirements in the micro range resulting from the size effects or use them for innovative approaches. Not only the forming processes themselves, but also the entire process chain from material development, the process steps before and after forming to the planning aspects of micro forming manufacturing were the subject of research. From 2007-2018 more than 60 researchers conducted research on 17 basic projects and 4 transfer projects, the latter being implemented together with industry partners from the accompanying industrial workgroup. With the resulting knowledge of the mechanisms and correlations, a tar- geted process design and connection was made possible for the process-reliable production of metallic components with a size of less than 1 mm and the necessary tools. In order to enable a high speed of innovation in mass production, the methods developed in the SFB are supported simulatively so that rapid product changes are possible. Using simulatively determined process parameters, the micro parts developed in only two steps can be fabricated using the thermal material accumulation developed in the SFB. Rotary swaging was qualified for mass production in the micro range by examining and controlling the technical and material aspects. The influence of the individual deep drawing operations on each other in a two-stage deep drawing process could be identified by tolerance engineering and a prediction of the required tolerances in each process step was possible. A synchronized production, with rates of up to 300 subassemblies / minute was made possible by production in linked parts and a tailor-made conveyor technology made possible. For the integrated planning and evaluation of the complete process chain for the microfabrication, the program μ-ProPlAn was developed and statistical methods for the analysis of interdependencies between production-relevant process parameters and material properties were integrated. Forming tools in mass production must have a long tool life, and be manufactured with high precision due to the small dimensions. Suitable tool materials with favorable tribological properties were qualified for this purpose. The following processes have been developed in the SFB for tool production: The laser chemical removal process (LCM) allows for quality-controlled, flexible processing without significant thermal and microstructural effects for cavities smaller than 200 μm. By optimizing micro-milling, it is possible to produce forming tools and tribologically active surfaces in a single processing step. The process control has been optimized by new mathematical approaches, taking into account the increased speed of innovation. Due to its hardness and tribological properties, diamond is a popular tool material, especially in the micro range. By the introduction of thermo-chemical-mechanical shaping of diamond for micro forming dies, a complex micro structuring of monocrystalline diamonds could be successfully implemented. Progress has also been made in the production and lifetime of graded tool materials (SLM and co-spray). Thanks to the development of a PVD process, hardenable 20 to 30 μm thin films of Al alloys and Al-steel bimetals with good forming properties can be produced, the latter also being continuous and therefore also suitable for mass production. A dropdown furnace was developed especially for micro heat treatment. On the basis of digital holography fast and accurate quality control of micro components could be provided basic and in cooperation with an industrial partner. Characterization methods for the micro range were developed for material testing. In order to be able to carry out comparable measurements, macro standards were also adapted to the micro range.

Publications

 
 

Additional Information

© 2025 DFG Disclaimer / Copyright / Privacy Policy

Textvergrößerung und Kontrastanpassung