EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Fused filament fabrication enables the production of ceramic, metallic and multimaterial components with complex geometries. The parts are generated by the selective extrusion of thermoplastic filaments highly filled with powder. Following, the polymers are removed and the parts finally sintered. Each step of the process has a strong influence on the final properties. Here, the influence of the shaping parameters of on the properties of zirconia parts and the phenomena occurring during shaping were analysed. Zirconia filaments with three powder contents (43 vol.%, 47 vol.% and 50 vol.%) were produced and used in the fused filament fabrication of bending bars. For the filaments with 47 vol.% parts with three different infill orientations (0°, ±45° or 90°) were additionally produced. Three-point bending tests were conducted on the specimens and the defects were identified with cuts in different sections. The interroad defects, the defects due to the material under- and overextrusion, and the defects caused by the shearing-off by the nozzle of the already deposited material were originated during shaping. The variability of the filament diameter further promoted the defects apparition. Moreover, the binder degradation and or moisture evaporation pores resulted in pores inside the extruded roads. The powder content and infill orientation influenced the apparition and orientation of all these defects, and the infill orientation had the largest influence on the bending properties.