Experimental and numerical investigations on locally foamable extrusions for additive manufacture of functional hybrid components

• Applicants: Professor Dr.-Ing. Klaus Dröder; Professor Dr.-Ing. Hans Jürgen Maier
• Subject Area: Polymeric and Biogenic Materials and Derived Composites ; Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: from 2020 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 442092412

The main objective of the proposed project is the production of hybrid functional components consisting of extruded aluminum profiles that are partly customized by additively manufactured polymers. In this context, the successful creation of a high-quality bond between the different material classes of metals and polymers remains a critical challenge. Hence, a new process approach shall be developed within this proposal, which will enable local foaming of the extruded profile’s surface. The open-porous structure in the peripheral region of the aluminum profile will then provide indentations and undercuts to establish a strong connection between the polymer component and the metal surface by form-closure. In order to gain comprehensive understanding of the process, the main factors influencing the bond strength shall be modeled numerically and experimentally. These include the parameters of polymer extrusion as well as the controlled modification of the geometrical pore structure at the surface of the profile, which can be adjusted by the foaming behavior of the extruded aluminum alloy. Suitable pore sizes and pore distributions shall be developed using simulation tools initially, which will then be realized experimentally by modifications of the composition of the aluminum alloy and an investigation of the process variables of extrusion. The numerical models shall be validated by measurements of the actual pore structures using computed tomography scans with an x-ray microscope. The properties of the functional hybrid components will also be evaluated using metallographic analyses as well as mechanical tests.

• DFG Programme: Research Grants