TiC对C—B_4C—SiC复合材料显微结构与性能的影响

THE EFFECT OF TIC ON THE MICROSTRUCTURE AND PROPERTIES OF C-B_4C-SiC COMPOSITE

本文就烧结助剂ＴｉＣ对Ｃ—Ｂ４Ｃ—ＳｉＣ炭／陶复合材料显微结构与性能的影响进行了研究，结果表明ＴｉＣ在烧结过程中发生了固相反应，在晶界生成了ＴｉＢ２，有效地促进了Ｃ—Ｂ４Ｃ—ＳｉＣ复合材料的烧结，抑制了晶粒的长大，使复合材料密度与强度大幅度地增加，电阻率下降；同时ＴｉＢ２在氧化时生成致密的ＴｉＯ２，包裹了易氧化的Ｂ４Ｃ和Ｃ，使制品难氧化，从而大大提高了制品的抗氧化性能。

The effect of agglutinant TiC on the microstructure and properties of C-B4C-SiC composite was studied,lt is found that TiC reactg with B.C to form TiB2 at the srain boundary in the sintering process,and sintering process was accelerated,the growth of grain was controlled. Consequently,the density and strength of the composite increase markedly and the specific resistance decreases a little. On the other hand,when the composite was oxidized,TiB, was first oxidized to dense TiO2 which wrapts up carbon and B4C particles, making them difficult to be oxidized. So the oxidation resistance of the composite increaseg greatly.