Fabrication of tough SiCf/SiC composites by electrophoretic deposition using a fabric coated with FeO-catalyzed phenolic resin

A hybrid processing route based on vacuum infiltration, electrophoretic deposition, and hot-pressing was adopted to fabricate dense and tough SiCf/SiC composites. The as-received Tyranno SiC fabric preform was infiltrated with phenolic resin containing 5 wt.% FeO and SiC powders followed by pyrolysis at 1700 °C for 4 h to form an interphase. Electrophoretic deposition was performed to infiltrate the SiC-based matrix into the SiC preforms. Finally, SiC green tapes were sandwiched between the SiC fabrics to control the volume fraction of the matrix. Densification close to 95% ρtheo was achieved by incorporating 10 wt.% Al2O3-Sc2O3 sintering additive to facilitate liquid phase sintering at 1750 °C and 20 MPa for 2 h. X-ray diffraction and Raman analyses confirmed the catalytic utility of FeO by the formation of a pyrolytic carbon phase. The flexural response was explained in terms of the extensive fractography results and observed energy dissipating modes.