Lithography-based ceramic manufacturing of porosity graded alumina and hydroxyapatite ceramics
NOHUT S. 1,2, KRALEVA I. 3, SCHLACHER J. 3, GEIER S. 1, SCHWENTENWEIN M. 1, BERMEJO R. 3
1 Lithoz GmbH, Mollardgasse 85a/2/64-69, A-1060, Vienna, Austria, Vienna, Austria; 2 Department of Mechanical Engineering, Piri Reis University, 34940, Istanbul, Turkey, Istanbul , Turkey; 3 Department of Materials Science, Montanuniversitaet Leoben, Franz Josef Strasse 18, A-8700, Leoben, Austria, Leoben, Austria
In this study, porous ceramic samples have been produced by using different concentrations of poly(methyl methacrylate) (PMMA) as pore-forming agent (PFA) in a photocurable slurry via lithography-based ceramic manufacturing (LCM). LCM is an additive manufacturing method that works according to the principle of selective curing of photosensitive formulation with the digital light processing concept. The mechanical properties and microstructural features were determined as a function of PFA concentration. Furthermore, the printed layer thickness, PFA particle size, and sintering temperature were varied to assess their influence on the resulting material properties. The results showed that the counterbalance effect between porosity and mechanical properties can be optimized by design of material composition and processing parameters according to the end application. Furthermore, multi-material LCM printing was evaluated in combination with the aforementioned PFA concept to create functionally graded ceramics (FGCs) with porosity gradients in different orientations. FGC combinations were produced by developing suitable suspensions, optimizing the debinding and sintering processes according to the single material thermo-elastic properties, design, and optimization of printing processes. The gradient properties of the samples were characterized by scanning electron microscopy. This contribution focuses on using alumina and hydroxyapatite as ceramic matrix materials to create functional and customized components. This includes components for different applications such as e.g., separation or catalysis from alumina, or for tissue engineering or bone replacement materials from hydroxyapatite.