Investigation Of Tailored Blank Production By The Process Class Sheet‐Bulk Metal Forming

Nowadays efforts are made to improve sheet metal manufacturing processes and forming capability. Functional sheet metal components, for example toothed synchronizer rings, show closely‐tolerated complex geometric features, especially in the automotive industry. Unfortunately sheet metal forming operations do not offer the possibility for complex shapes as do for example cutting technologies [1]. To avoid this restriction, the usage of semi‐finished products with a material pre‐distribution in the blank is investigated. So‐called tailored blanks are usually made of different materials or sheet thicknesses. A common way of joining diverse blanks is welding [2]. In most cases the joining has a significant influence on the consecutively forming process due to varying local mechanical properties [3]. Hence the manufacturing of tailored blanks with a defined sheet thickness characteristic by the process class “sheet‐bulk metal forming” is investigated. Subsequent the tailored blanks are provided for forming operations such as deep‐drawing and the direct forming of complex functional shape elements. Aim of the project is the manufacturing of circular blanks with a sheet thickening in the exterior area by an upsetting operation. At the beginning, FE‐based studies and physical experiments using blanks of DC04 are carried out, to create a fundamental knowledge base of the forming process. A comparatively large contact area between blank and forming tool, a three‐dimensional material flow and the low sheet thickness cause high process forces. Building up a multi‐stage upsetting process with different sequenced tool geometries is one approach to meet this challenge. The material flow out of the sheet center is realized step‐by‐step to lower the actual contact area and sequential the appearing forces