Biomorphic cellular ceramics

Biotemplating-a new concept for preparation of ceramic composite materials with biomorphic microstructures will be described. Biological carbon prefor ms (C-B-templates) were derived from different wood structures by high-temp erature pyrolysis at temperatures-between 800 and 1800 degrees C and used a s templates for infiltration with gaseous or liquid Si to form SiC- and SiS iC-ceramics. During high-temperature processing, the microstructural detail s of the bioorganic preforms were retained. Cellular ceramic composites wit h unidirectional porous morphologies and anisotrophic mechanical properties were obtained. The cellular composites show low density, but high specific strength and excellent high temperature stability.