Open-cell metal foams provide attractive properties, making them suitable for the use in various industrial sectors like lightweight design, biomedical engineering or chemical engineering. Due to their highly porous and light weight structure in combination with their base material, advanced mechanical and chemical properties are enabled. In this field, metal foams with triply periodic minimal surface (TPMS) lattice structures have emerged within the last decade. Their highly periodic three-dimensional structure leads to a material class with higher adaptability in terms of desired properties. Since there are nearly no investigations regarding Al-alloys as the base material within these structures, due to difficulties regarding 3D-printing of Al-alloys, different TPMS structures with an AlSi7Mg alloy are being manufactured and evaluated regarding their mechanical properties under compressive loading.

A novel manufacturing process, including modeling of the structures using the freeware MSLattice, 3D-printing of resin models and subsequent investment casting, is used to create gyroid- and diamond-based structures with relative densities of ρrel = 0.1, 0.15 and 0.2. For the evaluation of the mechanical properties, the foams are being examined under quasi-static compressive loading up to densification. To gain information on the elastic properties of these structures, additional compression tests with numerous hysteresis are performed and compared to non-destructively determined stiffnesses using resonance frequency damping analysis (RFDA). With these investigations, it is shown how cast Al-base TPMS structures behave under compressive loading in terms of elastic and plastic deformation, enabling a further understanding of the mechanical properties of cast TPMS structures in comparison to open cell foams with randomly orientated struts.