Optimization of Material Properties for Highly-Filled Thermoplastic Polymers used in Fused Filament Fabrication of Ceramics
Cano Santiago (1)*, Cajner Hrvoje (2), Gonzalez-Gutierrez Joamin (1), Sapkota Janak (1), Kukla Christian (3), Arbeiter Florian (4), Schuschnigg Stephan (1), Holzer Clemens (1)
(1) Montanuniversitaet Leoben, Institute of Polymer Processing - Styria - Austria, (2) University of Zagreb, Faculty of Mechanical Engineering and Naval Architecture - Zagreb - Croatia, (3) Montanuniversitaet Leoben, Industrial Liaison Department - Styria - Austria, (4) Montanuniversitaet Leoben, Materials Science and Testing of Polymers - Styria - Austria
Fused Filament Fabrication (FFF) is a material extrusion based additive manufacturing technique that enables the processing of thermoplastic filaments, which are selectively extruded and deposited in a layer-wise manner to create three-dimensional objects. Filaments of polymer-based compounds highly-filled with ceramic powders (ca. 40-60 vol.%), known as feedstocks, can be processed by means of FFF to shape ceramic parts. Such parts are then debound in order to remove the polymer from the feedstock. A highly porous structure is obtained, which is sintered at high temperatures to produce dense ceramic components. The use of highly-filled polymers constitutes a processing challenge, due to their high viscosity that complicates the fabrication by FFF. The material properties of compounds filled with zirconia (ca. 47 vol%) were optimized by the incorporation of an additional low viscosity component. Unfilled compounds were used as a reference system to evaluate the effect of the powder on the evaluated properties. It was observed that by adding the low component, the mechanical properties (flexibility, strength and stiffness) and feedstock viscosity are suitable for the production of filaments and the FFF process. Furthermore, the low viscosity component further promotes the defect-free removal of the major polymer fraction by leaching with a solvent.