Centrifugal Casting of Thin-Walled Ceramic Tubes from Preceramic Polymers

Thin‐walled (wall thickness, 100–2000 μm) mono‐ and bilayered ceramic tubes in the system Si–O–C–(N) were obtained by centrifugal casting of a polysiloxane/filler suspension. Si and SiC powders were dispersed in polyorganosiloxane/triethoxysilane solutions. After centrifugal casting in a Teflon tube with a rotational speed of 2000 rpm and subsequent cross‐linking at 130°C and 60 rpm, the tubes were pyrolyzed in argon or in nitrogen at 1400–1600°C. Bilayered tubes with controlled variation of porosity were obtained by overcasting the monolayer green tubes with a modified slurry composition.