Effect of slurries on the microstructure and mechanical properties of Cf/SiC composites via precursor pyrolysis

Cf/SiC composites were fabricated by Precursor Infiltration and Pyrolysis(PIP) with three different slurries. This paper studied the effects of the slurries on the microstructure and mechanical properties of their composites. It is pointed that the composites infiltrated with the slurry of PCS/cross-linking agent had a density of 1.78g·cm-3 and a open porosity of 4.95%, and its fabrication was only made of 9 times of infiltration and pyrolysis; The second composites infiltrated with PCS/Xylene/SiC had the highest density of 1.87g·cm-3 with smooth surface; And the last composites took on outstanding mechanical properties, the values of flexural strength, flexural modulus and fracture toughness were 455.9MPa, 90.6GPa and 18.9 MPa·m1/2 respectively. The results indicate that different slurries have different advantages, the composites could obtain the best characteristic if it was infiltrated with the most appropriate slurry in every fabrication circles.