Processes of the new production technology sheet-bulk metal forming allow a fast and efficient nearnet-shape forming of highly complex parts. Thus the need of energy and raw material as well as the production cycle time can be reduced. In order to guarantee these advantages by avoiding scrap and moreover to ensure the parts' geometrical requirements, production-related metrological solutions for an adapted inspection of parts and tools of sheet-bulk forming processes have to be developed. To fulfill the demands of the differing measuring tasks two prototypical measurement solutions are under development: a multi-scale multi-sensor fringe projection system allows for holistic inspections in feature adapted resolutions, whereas a fiberscopic fringe projection system captures the forming tool partly between forming steps. For the purpose of evaluating the metrological solutions' capabilities of capturing the geometry of filigree structures a comparison of both systems is presented in this work. To guarantee realistic results, the performed measuring tasks have to be comparable to the areas of applications both systems were designed for. During the development of the measuring systems the emphasis was put on the inspection of small complex geometries. These are most challenging for fast and reliable optical inspection under productionrelated conditions. By considering measurements of calibrated standards on the one side as well as of measuring tasks resulting out of real sheet-bulk metal forming processes on the other side a realistic comparison is assured. Next to the measuring systems' performances also an approach for combining the measurement data of both metrological solutions is shown. By combining the advantages of both measuring systems, highly detailed information for further interpretations of the forming processes can be provided.
The unique process of sheet-bulk metal forming (SBMF) represents a combination of sheet and bulk metal forming by inducing a three-dimensional material flow in sheet metals in a single forming stage. Within this paper two different applications of sheet-bulk metal forming are demonstrated. Hereby two different combined drawing and upsetting processes to realize parts with symmetrically and asymmetrically arranged functional elements are analysed. Finally, this contribution introduces a new machine technique which provides an improvement of the working accuracy of a forming machine and thus has a positive influence on the parts quality. The idea is to use electromagnetic ram guidance to counteract the displacement of the ram due to horizontal forming forces while forming of asymmetric parts.
Holograms are industrially used as decorative design elements to increase the value of products. As they are hard to copy, holograms are also used for brand protection and product identification. The state-of-the-art is to emboss holograms in the surface of polymeric foils and to apply them to products by adhesive bonding. Examples are holograms on credit cards, banknotes or identification cards. In this paper, a new method to emboss holograms in the surface of sheet metals is presented. By this, parts made of sheet metal such as decorative interior parts of cars, battery housings or packaging of cosmetic products can be equipped with holograms during their production process. Hence, adhesive bonding and the required additional handling operations are not necessary. An embossing tool and the results of experimental hologram embossing are described. Aluminium Al99.9, aluminium-magnesium alloy AW-5505, copper and zinc-coated deep drawing steel DC05 were used as sheet metals to be embossed.
Furthermore, a new method and a device to produce master holograms are presented. Master holograms are required to produce embossing dies with the hologram on its surface (referred to as shim). The device is based on a laser light source and a spatial light modulator (SLM). With help of the SLM, simultaneous transfer of 1920 x 1080 pixels of a Computer Generated Holograms (CGH) topography to a plate coated with photoresist is possible. Compared to todays industrial mastering of holograms which is done pixel by pixel, the time required for the process is much shorter. In addition, investment costs are lower compared to currently used electron-beam-lithography devices.
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