Manufacturing of complex functional components with variants by using a new metal forming process – sheet-bulk metal forming

Nowadays, traditional sheet metal and bulk metal forming processes are often reaching their limits, particularly in the automotive sector, if closely-tolerated complex functional components are required. In this paper, an approach for the direct forming of high-precision shapes starting from blanks will be presented and fundamentally analyzed. Aim of this new process-class, named “sheet-bulk metal forming”, is the direct forming of functional components with variants out of the sheet. In a first step, the complex interactions between regions of high and low strains, which are characteristic for sheet-bulk metal forming, have been investigated by simulations. Based on the identified process characteristic, new tool geometries and forming strategies for extrusion and deep-drawing processes have been developed to fine-control the local material flow for a defined filling of the target regions. A further enhancement of the mold filling can be achieved by a predistribution of material using tailored blanks with a defined varying thickness where material is transferred to its target regions to adjust special local mechanical properties. In the paper it will be also exemplified, that the desired process behaviour can be supported by local increased friction provided by tailored surfaces.