Properties of Porous SiC Ceramics Prepared by Wood Template Method

Porous SiC samples were prepared with three types of wood (poplar, pine, big cone pine) by simply embedding the wood charcoal in a powder mixture of Si and Sia, at 1600 and 1700 degrees C. The basic engineering properties such as density, porosity, pore size and distribution, and strength were characterized. The samples showed full conversion to mostly beta-SiC with good retention of the cellular structure of the original wood. More rigid SiC struts were developed for 1700 degrees C. They showed similar bulk density (0.5 similar to 0.6 g/cm(3)) and porosity (81-84%) irrespective of the type of wood. The poplar sample showed three pore sizes (1, 8, 60 mu m) with a main size of 60 mu m. The pine sample showed a single pore size (20 mu m). The big cone pine sample showed two pore sizes (10, 80 mu m) with a main size of 10 mu m. The bend strength was 2.5 MPa for poplar, 5.7 MPa for pine, 2.8 MPa for big cone pine, indicating higher strength with pine.