中文摘要：

针对Ti-Si-B_4C-C反应体系,在进行热力学分析的基础上,采用燃烧合成法制备了复相陶瓷粉体,采用XRD、SEM对反应产物的物相和组织结构进行表征,探讨了燃烧反应机理。研究结果表明,所制备复相陶瓷由Ti_3SiC_2、TiB_2、TiC三相组成,其质量分数分别为44.2%、27.9%、27.9%。Ti B2相以棱角分明的颗粒形态存在,TiC相以不规则的球形颗粒存在,两种颗粒弥散分布于具有典型层状结构Ti_3SiC_2基体中。Ti-Si-B_4C-C体系反应机理可以概括为Ti与C的燃烧反应、Ti-Si熔体的形成、B的还原与Ti_3SiC_2的合成、TiB_2的生成与长大四个基本过程。

英文摘要：

The composite ceramic powders of Ti- Si- B_4C- C system were prepared by combustion synthesis method based on thermodynamic analysis. The phase and microstructure of the products were respectively characterized by XRD and SEM. The mechanism of combustion reaction was discussed. The results show that the composite powders are composed of Ti_3SiC_2,TiB_2 and TiC,in which Ti_3SiC_2is matrix phase,TiB_2 and TiC are reinforcing phases. The mass fractions of Ti_3SiC_2,TiB_2 and TiC are 42. 7% to 45. 7%,26. 3% to 29. 5% and 27. 8% to 28. 0%.TiB_2 angular particles and TiC irregular particles are dispersively distributed in layered structure Ti_3SiC_2. The combustion reaction of Tiand C,the formation of Ti- Si melt,the reduction of B and the synthesis of Ti_3SiC_2,the nucleation and growth of TiB_2 occur in the process of Ti- Si- B_4C- C system combustion reaction.