THE GROWTH OF MULTI-STAR CVD BETA-SIC AND SIC TIC COMPOSITES/

The multi-star beta-SiC and SiC/TiC composites have been deposited by CVD method on graphite substrate. The precursors, SiCl4, TiCl4 and C3H 8 were used as silicon, titanium and carbon sources, respectively, and hydrogen as a carrier gas for deposition. The morphology of surface a nd polished cross section for the SiC and SiC/TiC composite deposited was observed by SEM. The crystal orientations and microstructrure were analyzed by XRD and TEM. The growth propagation of the multi-star bet a-SiC and the SiC/TiC composites is attributed to the twin-plane-reent rant-edge mechanism. The [220] is an intensely preferred orientation a s the twin axis of interpenetration twin configuration. The interface of SiC/TiC is severely strained as found in TEM image and dislocations are generated in the TIC phases owing to the mismatch of coefficient of thermal expansion.