Preparation of macro-porous SiCAl 2O 3 composites with polysilanes and polycarbosilanes

Abstract

Spongelike polycarbosilanes with 50% open porosity were prepared by pyrolysis of a mixture of polysilanes and polycarbosilanes at 650 °C in argon. Porous SiCAl 2O 3 composites were prepared by oxidation of the pyrolyzed preforms at 600 °C in air and subsequent infiltration with an aqueous Al 2O 3 slurry. Sintering was performed at 1600 °C in 1.5 MPa argon. The precursors were analyzed by infrared-spectroscopy and by thermal decomposition. The SiCAl 2O 3 composites were investigated by light microscopy, scanning electron microscopy, energy dispersive X-ray analysis and electron scanning microanalysis.