Fused Filament Fabrication of silicon carbide parts: A strategy for producing high-strength components

Fused Filament Fabrication (FFF) is a constant evolving additive manufacturing (AM) technology enabling the production of near-net-shape parts with complex geometries without requiring molds. While extensively applied to oxide ceramics such as alumina and zirconia, its application to non-oxide ceramics like silicon carbide (SiC) remains underexplored. Key challenges include defects arising from sintering operations and inherent porosity introduced by the 3D printing process. This original study examines the best strategy to produce fully dense and defect-free SiC through FFF method combined with pressureless sintering. Process parameters were systematically refined using Taguchi's method. Defects like delaminations and voids were characterized and correlated with filament ageing. By employing optimized parameters, printed parts exhibited fine, homogeneous microstructures along with mechanical performances comparable to commercial SiC grades. The resulting properties include a density of 3.14 g.cm-3 , a hardness of 2492 HV, a Young's modulus of 410 GPa, and an average flexural strength of 429 MPa with a Weibull's modulus of 9.0. Furthermore, this contribution highlights the significant influence of filament ageing on mechanical performance, providing valuable insights for the development of reliable SiC components via FFF.