摘要
研究了烧结碳化硅在１２００℃和１３７０℃高温条件下的动、静疲劳性能，结果发现由于烧结密度较低，材料的抗弯强度不高，但高温疲劳强度没有明显下降，并且动、静疲劳性能相近。断口观察和缺陷“冻结”分析表明在最大拉应力区附近的烧结缺陷的尖角处常是裂纹源，在此处萌生的裂纹沿烧结缺陷联结成为主裂纹并导致断裂。最后作者提出了陶瓷材料高温疲劳损伤的杂质空穴复合作用机制。
The static and dynarnic fatigue behaviour of sintered SiC at 1200℃ and l370℃ are investigatted. Itis discovered that the bending strength of the material is not very high because of its low sintered density, but thedifference between the fatigue strength at elevated and room temperature is not so high, and the static and dy-namic fatigue strength are almost the same. The fractographic observation and the analysis of defects 'freezing' show that the pointed edge of defect near the maximtim tensile stress zone is always the cracking source, and theconnection of the microcracks occurred here becomes the main crack which induce fracture, A mechanism of'combined effect of cavity and impurity' for the fatigue of ceramics at elevated temperature is proposed.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
1995年第5期501-506,共6页
Journal of The Chinese Ceramic Society
基金
北京市自然科学基金资助项目
关键词
碳化硅
高温疲劳
断裂机理
陶瓷
疲劳
力学性能
silicon carbide, fatigue at elevated temperature, fracture mechanisms
