An aqueous-based carbon black binder and post-treatment for enhanced binder jetting of SiC ceramics

Binder jetting technology holds great potential for fabricating complex silicon carbide (SiC) ceramics, but the lack of specialized binders and post-treatment methods often results in suboptimal surface quality and mechanical properties of both the green and final parts. This study introduces a novel aqueous-based carbon black binder for the fabrication of Si-SiC composites via binder jetting (BJ), followed by carbon dispersion impregnation, pyrolysis, and liquid silicon infiltration (LSI). The binder was characterized in terms of its rheology, printability, and wetting behavior on SiC powder, demonstrating superior performance compared to commercial binders. The carbon black binder improved the surface quality of green parts, reducing roughness from 23.88 μm to 14.38 μm. Additionally, the SiC/C preform treated with carbon dispersion showed better pore distribution and reactivity during sintering. After LSI, the final composite exhibited a flexural strength of 319.32 ± 9.12 MPa, representing a 30 % improvement over phenolic resin-treated composites. These findings highlight the potential of carbon black binders in enhancing the composition and mechanical properties of binder jetting SiC composites, providing a reference for future material developments.