20 – 30% of tools in bulk forming are manufactured from cemented carbides. In a conventional manufacturing process standardized carbide blanks are made first. These blanks are tooled by costly and complex procedures to achieve the final geometry of the forming tool. This process chain includes two cost-intensive steps, generating and cutting of cemented carbides, compensating each other in the overall process. An additional coating increases durability to wear. Since surface quality of tools in bulk forming affects the quality of work pieces significantly, forming tools are finished by burnishing. Burnishing of the tool surface is usually carried out by expert employees.
This project aims on substituting generating and cutting of cemented carbide blanks by additive manufacturing. In this stage of production a near-net-shape blank (NNS-blank) is generated directly from carbide powder. This can be achieved by different additive manufacturing processes as 3D-metal-printing or by procedures with a negative mould of the NNS-blank. When using a negative mould, the powder can be additionally compressed by machine hammer peening (MHP) before sintering. By the use of additive manufacturing a time and cost advantage is spawned over the conventional process. The application of machine hammer peening to finish tool surfaces provides further time and technological benefits. By achieving comparable surface characteristics, MHP requires just a fractional amount of time as manual burnishing. Further more, specific tool areas can be designed stress-related using an increase of hardness by cold forming and placing residual stresses.
In a first step forming forces are determined in a simulative reference forming process, which are used to calculate the resulting stresses of the forming tool. Thereby, residual stresses can be placed specific in critical tool areas by machine hammer peening, as well as surface finish will be performed. In sliding compression tests manufactured tool samples are investigated tribologically and wear characteristics are determined.
Finally, the tools of the new developed process chain are tested under real, industrial conditions and their performance is compared to conventional manufactured shaping tools.
The PtU would like to thank the partner institutes and the participating companies for their support in the implementation of this project:
- Institut für Angewandte Materialien (KIT)
- Institut für Fertigungstechnik (TU Wien)
- RHP-Technology GmbH
- accurapuls GmbH
- AT Space GmbH
- Boehlerit GmbH & Co.KG
- DIMAB Spezialschweißarbeiten GmbH & Co. KG
- Ecoroll AG Werkzeugtechnik
- Ernst Wittner GesmbH
- Felss Systems GmbH
- Gerhard Rauch Ges.m.b.H.
- INDAT Modellbau Formenbau Werkzeugbau GmbH
- Kamax Tools and Equipement GmbH
- LG Technology Center Europe
- LS-Mechanik GmbH
- Neuman Aluminium Fließpresswerk GmbH
- Hartmetall-Werkzeugfabrik Paul Horn GmbH
- Rosswag GmbH
- SBI Produktion techn. Anlagen GmbH & Co.KG
- TiroTool Werkzeugsysteme GmbH
- Thomas GmbH
- Thyssen Krupp Presta AG
- Wezel GmbH Kaltumform-Technik