Non-oxide CMC fabricated by Fused Filament Fabrication (FFF)

The present study introduces an approach to additively manufacture non-oxidic Ceramic Matrix Composites (CMCs) by the Material Extrusion (MEX) based Fused Filament Fabrication (FFF). Therefore, highly SiC particle filled thermoplastic filaments were developed containing short fibers and/or long fibers to maintain shape during the thermal treatment and exhibiting flaw tolerant behavior. Polymer Infiltration and Pyrolysis (PIP) was applied to densify the microstructure. It is shown that a low content of long fibers of about 5 % can already exhibit damage tolerance comparable to steel reinforced concrete. Thus, the mechanical behavior is different to conventional fiber composites with significant higher fiber volume content. Nevertheless, these results enable new opportunities for producing advanced complex CMC components by means of Additive Manufacturing (AM).