Microstructure of Silicon Carbide Prepared by Reaction-Sintering

Abstract

Reaction-sintered bodies of β-SiC were prepared in vacuum by impregnation of gaseous or liquid silicon into the following powder compacts; non-graphitizable carbon, artificial graphite and colloidal graphite. Microstructure of the resulting reaction-sintered bodies were observed with electron microscope and reflected optical microscope, and then it was found that the microstructure of reaction-sintered body by gaseous silicon differed greatly from that of reaction-sintered body by liquid silicon. The microstructure of the former could be explained on the basis of multi-grain-coalescence model which was previously proposed by the authors, while the microstructure of the latter was resulted from a predominant action of liquid silicon in the solution-precipitation mechanism.