Production technology for hybrid-lightweight-structures with aluminum foam core-sub-project within the cluster of excellence MERGE

Abstract

Production technology for hybrid-lightweight-structures with aluminum foam core - Sub-project within the Cluster of Excellence MERGE MERGE is the one and only Federal Cluster of Excellence in the field of research and development of innovative key-technologies for lightweight structures in Germany. The main objective of the Cluster “Merge Technologies for Multifunctional Lightweight Structures” is to create lightweight and material-efficient components by merging currently separated production processes of different material groups. One focused topic is the development of lightweight-sandwich-composites made of metal foam and fiber-reinforced plastics (FRP). Because of their low density, high energy absorption capability, stiffness and strength and very good damping behavior metal foams are excellently suitable for lightweight structures. The combination of metal foam with sheet metal covers as sandwich structure is already used in manifold applications. In order to enhance the level of lightweight construction in metal sandwich structures, the substitution of metal cover sheets with fiber-plastic composites provides an effective approach. By adapting the thickness of core and FRP layers in combination with high performance fibers and load specific design customized structural properties are possible to be to be realized. One key aspect is the bonding of both components. To find an optimal combination many experiments have been carried out to investigate the influence of various parameters, e.g. the modification of the metal foam surface and thermoplastics or the use of adhesive-agents. The permanent bonding of the sandwich components is realized in a pressing process. Therefore, the sandwich components need to be preheated. To increase the energy efficiency, a technology will be developed using the process heat of the foaming instead of additional preheating. For achieving a high functional density, the injection molding processes can be used to implement thermoplastic elements, e.g. stiffening rips or mounting interfaces, into these sandwich structures based upon metal foam cores