Cellular Metals show a great potential for a wide range of technical applications due to their unique mechanical and physical properties. Metallic sponges have found first applications in heat-exchangers and filters, but hitherto neither open nor closed cell materials are commercially used for the manufacture of light-weight structural components. The major obstacle is the irregular structure of most cellular metals, induced by the limitations of the respective manufacturing method, which hinders the exact prediction of the material properties. Therefore, improvement of the production processes, the three-dimensional characterisation of the cellular structures and the development of appropriate methods for mechanical testing are subjects of current research activities. A new approach for the optimisation of metallic open-cell sponges is rendered possible by the use of rapid-prototyping. Almost arbitrary structures, tailored to the demands of the intended application, can be directly fabricated from CAD data sources. Software systems for structural optimisation can play a decisive role in the process of designing these structures, which can be directly used as lost models in the investment casting process. The underlying casting techniques have been developed in the Foundry Institute of Aachen University during several research projects. They allow for the use of a wide range of alloys as raw material for the fabrication of cellular metals. This technique is now used for the structural optimisation of metallic sponges.
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