常压烧结碳化硅陶瓷的表面裂纹对其力学性能的影响  

Influence of Surface Cracks on Mechanical Properties of Solid-Phase Sintered Silicon Carbide Ceramics

作　　者：杨晓[1] 黄政仁[1] 刘学建[1] 

机构地区：[1]中国科学院上海硅酸盐研究所、高性能陶瓷和超微结构国家重点实验室,上海200050

出　　处：《硅酸盐学报》2014年第7期841-845,共5页Journal of The Chinese Ceramic Society

摘　　要：以常压烧结碳化硅陶瓷材料(SSiC陶瓷)为研究对象,开展陶瓷表面裂纹及其对力学性能影响的研究。结果表明,当裂纹尺寸小于40μm时,SSiC陶瓷的弯曲强度迅速降低55%;裂纹尺寸约50μm以后,弯曲强度的下降趋于平缓。通过曲线拟合及实验验证得到了弯曲强度对不同裂纹尺寸的关系式。通过对裂纹方向的研究,建立了裂纹方向对材料弯曲强度产生影响的模型。Silicon carbide ceramics were prepared via solid-phase sintering as SSiC. The influence of surface cracks on the corre- sponding bending strength was investigated. The results show that the strength of SSiC ceramic is decreased by 55% when the crack size is〈40μm, and the decreasing trend of bending strength becomes slower in the presence of the longer cracks. A fitted equation was proposed to calculate the bending strength as a function of crack size. The inclined angle of surface crack was also discussed, and a corresponding model was established to analyze the influence of crack inclined angle on the bending strength.

关 键 词：碳化硅陶瓷 表面裂纹尺寸 表面裂纹倾斜角 弯曲强度 

分 类 号：TQ174.75[化学工程—陶瓷工业]