Infiltration and pyrolysis of polytitanocarbosilane in an Si-Ti-C-O fabric/mullite porous composite

Incorporating Si-Ti-C-O fabric into a mullite matrix is expected to increas e the fracture energy of mullite ceramics. The present paper describes the processing of an Si-Ti-C-O fabric/mullite/polytitanocarbosilane composite. A polytitanocarbosilane (a precursor of Si-Ti-C-O fiber)/xylene solution wa s infiltrated into a laminated porous mullite composite with 35-37 vol% fab ric and thermally decomposed to an amorphous solid at 1000 degrees C, in an argon atmosphere, to decrease the porosity and residual stress induced by the difference in thermal and mechanical properties between the Si-Ti-C-O f abric and the mullite. The decrease in porosity of the composite with pyrol ysis of the precursor polymer was analyzed theoretically, and those results were used to control the effective experimental parameters. The infiltrati on/pyrolysis process was repeated eight times to produce a composite of 90. 4% theoretical density. The composite exhibited significant pseudoductility , with a fracture energy of 11.4 kJ/m(2) and a flexural strength of 290 MPa .