Abstract
High dense SiC ceramics were sintered to investigate the effect of crystallite size on thermal and electric conductivities. β-SiC is difficult to sinter in a high dense form without any additive even if ultra fine powder is used as a starting powder. In this work, nanometric SiC powder prepared by mechanochamical processing was subsequently consolidated by Spark Plasma Sintering method (SPS). The β-SiC with a relative density of higher than 95% and a crystallite size of 50nm was successfully consolidated. The crystallite size was evaluated by the broadening peak analysis of x-ray diffraction pattern and TEM observation. To obtain the other SiCs with different crystallite sizes, commercial powders of β-SiC were also sintered with the additives by SPS. Their thermal and electric conductivities were investigated with their crystallite sizes and morphologies.
