TEM/EELS Characterization of a Sintered Polycrystalline Silicon Carbide Fiber

Abstract

A sintered, polycrystalline SiC fiber has been characterized by TEM and EELS. The fibers consist primarily of ␣-SiC (6H-polytype) with a mean grain size on the order of approximately 1 µm. Poorly organized turbostratic carbon is located within porous regions between some grain boundaries and triple junctions of the SiC. In addition, 100 nm spherical boron carbide precipitates are observed intragranularly within the SiC grains. These precipitates have a rhombohedral crystal structure with an approximate stoichiometry of B 4 C.