Additive Manufacturing of Bio-Based SiSiC Ceramics from Wood Polymer Composites

Conventional manufacturing of silicon carbide (SiC) ceramics is associated with a high consumption of energy and resources. In this paper, an alternative sustainable process route is presented for the manufacturing of bio-based silicon-infiltrated SiC ceramics (SiSiC) on the basis of a wood polymer composite (WPC) with a high wood content. The thermoplastically processible WPCs are shaped by means of Fused Filament Fabrication (FFF) and Fused Granulate Fabrication (FGF) into green bodies, which are then transformed into ceramics in pyrolysis and siliconization processes. The resulting SiSiC structures reach densities up to 2,6 g/cm³ and bending strengths up to 230 MPa. With optional hexamethylenetetramine (hexa)-infiltration, the SiC content in the SiSiC could be increased significantly. Key features of the process are a high degree of design freedom, low tool wear, and particular suitability for SMEs. The use of renewable raw materials as well as reduced process costs enable the fabrication of ceramics with consideration of sustainable aspects. The process route is shown in Fig. 1.