Properties of porous SiC ceramics prepared by wood template method

Abstract

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 SiO2 at 1600 and 1700°C. The basic engineering properties such as density, porosity, pore size and distribution, and strength were characterized. The samples showed full conversion to mostly β-SiC with good retention of the cellular structure of the original wood. More rigid SiC struts were developed for 1700°C. They showed similar bulk density (0.50.6 g/cm3) and porosity (81-84%) irrespective of the type of wood. The poplar sample showed three pore sizes (1, 8, 60 μm) with a main size of 60 um. The pine sample showed a single pore size (20 μm). The big cone pine sample showed two pore sizes (10, 80 μm) with a main size of 10 μm. 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.