THE EFFECT OF SILICON ADDITIVE ON THE STRUCTURE AND PROPERTIES OF C-B_4C-SiC COMPOSITE
THE　EFFECT　OF　SILICON　ADDITIVE　ON　THESTRUCTURE　AND　PROPERTIES　OFC－B_4C－SiC　COMPOSITE

A Preliminary study of the effect of silicon additive on the structure and properites of C-B_4C-SiC composite was conducted. A liquid Phase has formed and the liquid Si reacts with C to form SiC at the grain boundary when sintering, which accelerates the sintering process and retards the grain growth. Consequently, the density and strength of the composite increase markedly. And the increase in the density increases the oxidation resistance and decreases the specific resistance of the composite. Furthermore,the C-B_4 C-SiC composite has good heat-shock resistance. The phenomena may be dueto the strengthening and toughening of microcracks.