Monolithic SiOC Ceramics with Tailored Porosity

摘要

Mixing two catalytically cross-linking liquid polysiloxanes leads to porous but crack-free bodies after pyrolysis at 1100 deg. C in nitrogen. The low viscosity of the polysiloxanes allows the application of polymer-based moulding techniques like casting of complex-shaped SiOC components. Porosity and pore formation can be varied by changing the mixing ratio of the polysiloxanes. Pore formation affects strength, elastic modulus, fracture toughness, and creep behaviour. Four Point bending strength varies between abut 125 and 150 Mpa (specimen size 3.5 x 3.0 x 50 mm~3).