CHEN  Yuhong ¹ YANG Heping ¹ JIAN Xuehong ² CHEN Baiyi ²

(1. School of MSE, North University for Ethnic Minorities, Yinchuan 750021; 2. Ningxia Mechanic Institute, Yinchuan 750021)

Abstract:In this paper, SiC-TiB₂ composite was prepared by boron (B) and carbon (C) as sintering additive via presureless sintering. The effective of additive content and sintering temperature on preparation had been reached in detail.The results show that: when the B content in region of 0.4 -2% , sintered density decreased with B content increased, the best densification was achieved when the B content was 0.4%. Sintered sample density reduced with the increasing of C content in region of 2-3%. The maximum sample density was achieved in C content of 3%, then the density decreased with the C content increased. By comparing XRD pattern of the starting powders and sintered samples, it can be found that the new phase did not produced during sintering, indicated that sintering process was solid-state sintering mechanism. Conclusion:When the carbon content was 3%, boron content was 0.4% respectively and sintering temperature was about 2180℃, SiC -TiB₂ composite had best density.

Keywords:SiC-TiB₂ composite, pressureless sintering, sintering additives, densification, sintering mechanism