Simultaneous infiltration of submicron SiC powder and AHPCS during electrophoretic infiltration: A new straightforward process to synthetize SiCf/SiC composites

Silicon carbide fibers-reinforced silicon carbide (SiCf/SiC) composites were synthetized using the electrophoretic infiltration (EPI) process. Slurries included 50 wt.% of submicron SiC powder, about 1 wt.% of polyethylenimine as dispersant and 45 mg mL−1 of allylhydridopolycarbosilane (AHPCS) as pre-ceramic precursor in an ethanol/toluene solvents mixture at pH* 8.9. Formulation of the slurries was optimized by zeta potentials and viscosity measurements. The originality of the process presented herein is that AHPCS was directly infiltrated during the EPI, and not in a second processing step such as polymer impregnation. Densification of the resulting composites was achieved by pyrolysis of the AHPCS at 1600 °C under an argon flow. Density measured by the Archimedes' method was 74% of the SiC theoretical density.