Incremental sheet forming of tailored hybrid metal/polymer/metal sandwich composites for engineering and biomedical applications

• Applicant: Professor Dr.-Ing. Johannes Buhl, since 1/2024
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 464798082

Metal/polymer/metal sandwich composites (MPM) have proven their potential for application in the aerospace and automotive industry due to their lightweight potential and improved mechanical properties. Moreover, their application in biomedical fields is promising thanks to the arbitrary cus-tomization of their mechanical properties improving the comfort criteria with human bones in case of e.g. cranial reconstruction. Besides, customizing acoustic, thermal, and electrical properties are possible with MPM. Therefore, the main concern of the proposal is to process highly individualized parts of such sandwich sheets. Based on the nature of incremental sheet forming (ISF) - a die-less forming process delivering 3D complex shaped parts in a cost-efficient way - producing failure-free, geometrically stable parts made of such multilayered materials by ISF represents a substantial sci-entific challenge. The scope of the investigation is divided into two phases. In the 1st phase, a basic understanding of the forming behavior and failure mechanisms of formable MPM-sheets at room temperature, considering different materials, geometric and ISF-process conditions by experiments to be used for modelling and finite element simulation, is fore-seen. As a result, an optimized process window for the MPM sheets and a robust model will be giv-en using a strategy based on a scaling-up simulation and validation approach starting from the mono-materials, their interfaces, and finally, the shaped components. For this purpose, an exten-sive materials characterization has to be accomplished.In the 2nd phase, extending the knowledge from the 1st phase to cover the biocompatible MPM-sheets containing typically hard-to-shape core materials at room temperature like PEEK or PMMA. According to the state of the art in this area, the bonding quality and the size of the pro-duced sheets are still demanding challenge, actually being under development. So, appropriate ap-proaches have to be developed, e.g. heat-assisted ISF. Moreover, the influence of processing on residual stresses and early failure depending on temperature will be focused to be used for extend-ing the simulation.

• DFG Programme: Research Grants
• Ehemalige Antragsteller: Dr.-Ing. Mohamed Harhash, until 5/2023; Professor Dr.-Ing. Heinz Palkowski, from 5/2023 until 1/2024