Material extrusion additive manufacturing of advanced ceramics: Towards the production of large components

Thermoplastic extrusion based additive manufacturing (MEX-AM), is a very interesting fabrication method for the shaping of larger ceramic parts. Commercial filaments are currently available in the market, but due to the lack of information from the suppliers, it is not easy to select the suitable filament material for the 3D printing of individual ceramic objects. In this study, three commercial yttria-stabilized zirconia (YSZ) filaments provided by Fabru GmbH, SiCeram GmbH and PT+A GmbH were investigated. According to our results, it is possible to print YSZ filaments with extremely different flexibility and rheological properties. Compared to the other two filaments, the Fabru filament resulted in significantly higher flexibility, but the extrusion pressure to print it through a 0.25 mm nozzle was significantly higher at 150 °C. Interestingly, in the SiCeram filament, a grain orientation effect could be observed. Based on STA analysis it can be assumed that for the Fabru filament, the polymer which decomposes at a high temperature can already be removed by solvent debinding (SD). Finally, 70 mm tall cup structure including overhang features and different wall thicknesses was used to evaluate the printing and post-processing of YSZ filaments.