Fused Filament Fabrication of Alumina/Polymer Filaments for Obtaining Ceramic Parts after Debinding and Sintering Processes

In this paper, a hybrid commercially available alumina/polymer filament was 3D printed and thermally treated (debinding and sintering) to obtain ceramic parts. Microscopic and spectroscopic analysis was used to thoroughly characterize the green and sintered parts in terms of their mesostructured, as well as their flexural properties. The sintered samples show an alpha alumina crystalline phase with a mean density of 3.80 g/cm(3), a tensile strength of 232.6 +/- 12.3 MPa, and a Vickers hardness of 21 +/- 0.7 GPa. The mean thermal conductivity value at room temperature was equal to 21.52 +/- 0.02 W/(mK). The values obtained through FFF production are lower than those obtained by conventional processes as the 3D-printed samples exhibited imperfect interlayer bonding and voids similar to those found in the structures of polymeric FFFs. Nonetheless, the highly filled ceramic filament is suitable for use in affordable and easy-to-operate FFF machines, as shown by the cost analysis of a real printed and sintered FFF part.