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用溶胶-凝胶方法制备室温强度为935—1110MPa、断裂韧性9.7MPam~(1/2)的ZTA-SiC_W复合陶瓷。经X射线衍射分析、透射电子显微镜、扫描电子显微镜等手段研究其显微结构和断口特征。结果表明,晶须得到了很好的分散,基体有显著的织构特征,晶须与基体之间除了一部分常见的多晶相接型关系,还有大量的穿晶及穿晶相接型关系。断口上有相当数量与局域晶须群密切相关的二次裂纹。局域晶须群对扩展裂纹的协同阻挡形成二次裂纹可能是晶须群增强增韧的一种新方式。
ZTA-SiC_W composite ceramics with room temperature strength of 935-1110MPa and fracture toughness of 9.7MPam ~ (1/2) were prepared by sol-gel method. X-ray diffraction analysis, transmission electron microscopy, scanning electron microscopy and other means to study the microstructure and fracture characteristics. The results show that the whiskers are well dispersed and the matrix has obvious texture characteristics. In addition to the common polycrystalline phase connection between the whisker and the matrix, there are also a large number of transcrystalline and transcrystalline phase connections . There is a considerable amount of secondary cracks on the fracture surface that are closely related to the local whiskers. The formation of secondary cracks by the synergistic barrier of local whiskers to the extended cracks may be a new way to enhance the toughening of whiskers.