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: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 442092412

Hybrid functional structures made of different materials such as metal, plastic and reinforcing fibres enable resource-efficient and sustainable solutions for the production of functional, weight-optimized components. The studies on the production of hybrid functional structures made of aluminum foam and the polymer ABS show that the resulting composite strengths have a fundamental potential for a strong hybrid connection compared to similar material pairings. The analyses used (simulations, XRM analysis) have contributed to the understanding of the failure mechanisms of the hybrid composite and the infiltration behavior through the additively applied polymer. The detachment of the polymer from the pores under load and the limited fillability of the pores due to air inclusions are currently obstacles that must be reduced or eliminated by modifying the metal foam and the polymer. Until now, only a small percentage of the open pores on the surface have contributed to the actual bond strength. Perforations in the cell walls between the individual pores can create an opportunity for deeper infiltration and increase the number of undercuts for an improved bonding effect. They also serve to evacuate the air when applying the polymer. Furthermore, stiffening the polymer with short fibers can increase the tensile strength and overall stiffness. To achieve this, it is necessary for the reinforced polymer to enter the pores, which is to be systematically investigated with the help of process simulation and corresponding analytics based on experimental test series. The use of aluminum chips makes it possible to save energy and resources throughout the entire process chain, as this eliminates the need for the costly and energy-intensive production of metal powder.

• DFG Programme: Research Grants