Component Optimization by Forging of Composite Aluminum Extrusions

• Applicants: Professor Dr.-Ing. Bernd-Arno Behrens; Professor Dr.-Ing. A. Erman Tekkaya
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: from 2009 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 138690682

The benefit of multi-material components is characterized by the material-specific advantages of the used mono materials. The components are specifically adapted to the current requirement profiles. The object of this cooperation project is to study the process chain of compound extrusion and subsequent forging for the production of continuously steel-reinforced aluminum components.The manufacturing of partially and continuously reinforced components by combining hybrid extrusion and forging was investigated and the interactions between the processes were studied successfully. In the field of extrusion, a stable process control for rotationally symmetrical, partial composite extrusion could be realized and a pre-calculation of the reinforcing element position was achieved. It could be shown that it is possible to reinforce non-rotationally symmetrical profiles. Furthermore, the feasibility of the process combination of partial and continuous composite extrusion was demonstrated. For forging of partially and continuously reinforced raw parts, the change in position of the reinforcing elements during the material flow in the semi-finished aluminum parts was optimized on the basis of FEM simulations and experiments. In the following the influences on the joining zone quality were identified and qualified.Based on the results described, the possible product range shall be defined and extended in the second application phase by increasing the degree of complexity of the distribution of the reinforcing elements. From the superior target of adjusting a locally adapted distribution of the reinforcing elements in the composite part the following aspects are derived to be considered:- Hot extrusion of locally reinforced semi-finished products with non axially-symmetric cross section- Embedding of non-rotationally symmetric reinforcing elements- Manufacturing of profiles with excentric position of the reinforcing elements- Process design of the combination of continuous and discontinuous composite extrusion In the area of forging, the following issues will be addressed:- Analysis and control of the material flow in forging- Design of the geometry of the forging slug- Inhomogeneous preheating of the reinforced semi-finished aluminum parts for controlling of the formability the reinforcing elementsImportant milestones for both processes are the isolation and subsequent combination of corresponding process windows that consider the shape and the position of the reinforcing elements in the component. This also includes the characterization of the bonding zone and the component properties

• DFG Programme: Research Grants