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Cellular structures with modified strut properties by replicating a 3D printed PolymerWednesday (07.10.2020) 16:00 - 16:20 Room 1 Part of:
Established manufacturing methods for cellular ceramics, such as the replica method, direct foaming or sacrificial template method are useful for a fast and cheap production of foams with a homogeneous distribution of pores but are limited in terms of shaping. Additive manufacturing processes are therefore used to produce complex geometries, which often exhibit low strength due to internal porosity and surface defects. In comparison, 3D printing of polymers is much more advanced and cheaper. For this reason, the advantages of polymer 3D printing and the replica method were combined in this work to produce cellular structures with individual micro and macro structure.
First, we investigated the influence of pore shape and periodicity on the mechanical properties and microstructure of the cellular ceramics. Therefor we printed polymer templates with different strut shapes and replicated them with an aluminum oxide slurry. As a reference, we also produced 30ppi foams from PU templates. The main characterization was done by micro-CT, SEM and compression tests. With this technique it was possible to produce cellular ceramics with 15% higher compressive strength compared to conventional 30ppi foams with the same porosity.
For further modifying the struts, a sol-gel process with TEOS was used to form mullite on the surface, which improved the strut strength from 261MPa to 291MPa.