中文摘要：

以二硼化锆、硅和活性碳为原材料，在1850℃、20MPa条件下，采用反应热压烧结工艺制备出了SiC／ZrB2陶瓷基复合材料。研究了添加剂（硅和活性碳）含量对ZrB2陶瓷烧结行为和力学性能的影响。借助x射线衍射和扫描电镜分析了复合材料的物相组成和微观结构。研究结果表明：添加剂可以显著提高复合材料的烧结致密度和力学性能。复合材料的XRD衍射图谱中只有ZrB2和SiC的衍射峰。当添加剂含量为12wt％时，复合材料的弯曲强度和断裂韧性分别达到584MPa和7．25MPa·m1/2。显微结构分析表明，致密度的提高、晶粒粒径的减小以及断裂模式的转变是复合材料力学性能提高的主要原因。

英文摘要：

SiC/ZrB2 ceramic matrix composites were prepared by reactive hot pressing at 1850℃ under 20 MPa with zirconium diboride, silicon, activated carbon as raw materials. The effects of sintering additives （ silicon and activated carbon） content on sintering behavior and mechanical properties of ZrB2 were studied. Phase composition and microstructure of the composites were analyzed by XRD and SEM, respectively. The results indicate that the sintering additives could significantly improve the densities and mechanical properties of the composites. Only the diffraction peaks of ZrB2 and SiC were found in the X- ray diffraction patterns of the hot-pressed ceramics. For the specimen with sintering additives content of 12wt%, flexural strength of 584 MPa and fracture toughness of 7.25 MPa · m1/2 were obtained. It seems that the improvement in mechanical properties was attributed to the improvement of density, the decrease of grain size and the change of fracture mode.