ADDITIVE MANUFACTURING (DIW) OF CARBON-CARBON CERAMIC MATRIX COMPOSITES

Additive manufacturing of carbon materials is a more recent and challenging field still in its early stages of development, particularly for creating dense structural components like carbon-carbon composites. Traditional manufacturing routes of carbon-carbon composites suffer high costs, extensive production times, and geometric constraints. This study explores the production of complex-shaped, dense crack-free carbon-carbon composites via DIW in a single sintering step. The presented procedure aims to eliminate further pyrolysis steps to cut the production time and cost by formulating carbon-based inks with optimized properties. These inks were formulated using phenolic resin as matrix precursor, short (100 µm) carbon fibers as reinforcement and nano sized graphite particles as fillers dispersed in a solvent medium. Iterative optimization of ink rheology enabled the reduction of solvent content to 6.50 vol.%, thereby minimizing volumetric shrinkage and mass loss during carbonization. Characterization via the Archimedes method and Scanning Electron Microscopy (SEM) revealed that the resulting composites exhibit densification levels with apparent densities reaching 1.67 g/cm³ and total porosities as low as 10.18%. Furthermore, the integration of continuous carbon fibers provided anisotropic structural constraints that mitigated shrinkages along their paths. This research demonstrates that the combination of optimized ink rheology, optimized printing parameters, and controlled pyrolysis, facilitate the fabrication of complex architecture carbon-carbon composites, such as gyroid lattices and multi-walled nose cone components. These integrated processes result in predictable thermomechanical responses and structural stability under extreme environmental conditions.