Effect of temperature gradients and stress levels on damage of C/SiC composites in oxidizing atmosphere
Effect of temperature gradients and stress levels on damage of C/SiC composites in oxidizing atmosphere
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DOI：
10.1016/j.msea.2006.05.062
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发表时间：
2006-08
期刊：
影响因子：
6.4
通讯作者：
H. Mei;Lai-fei Cheng;Litong Zhang;Yongdong Xu
中科院分区：
文献类型：
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作者：
H. Mei;Lai-fei Cheng;Litong Zhang;Yongdong Xu
研究了C/SiC复合材料在ΔT1of 500℃，ΔT2of 400℃，100MPa， ΔT3of 300℃，150MPa循环下的应变响应。测量的热弹性应变范围为ΔT1保留0.209%，ΔT2保留0.168%，ΔT3保留0.122%，与施加的应力水平无关。热循环蠕变应变的非线性变化可以通过改变其速率来反映复合材料的损伤演变过程，该速率取决于温度梯度和外加应力。经过104次热循环后，复合材料的强度、模量和破坏应变分别保持了初始性能的60.29%、84.2%和59%。观察到循环试样的涂层裂纹垂直于外加应力，并以相对规则的间距排列，纤维通过这些裂纹被表面氧化。
Strain response of a C/SiC composite, which is cycled with ΔT1of 500°C at 50MPa, ΔT2of 400°C at 100MPa and ΔT3of 300°C at 150MPa, was investigated. Measured thermo-elastic strain ranges are found to retain 0.209% for ΔT1, 0.168% for ΔT2, and 0.122% for ΔT3, independent upon the applied stress level. Non-linear variations of thermal cycling creep strain can reflect damage evolutions of the composites by changing its rate, which depends on temperature gradient and applied stress. After 104 thermal cycles, strength, modulus, and failure strain of the composites retain 60.29%, 84.2%, and 59% of the initial properties, respectively. The coating cracks of the cycled specimens are observed to be perpendicular to the applied stresses and arranged at relatively regular spacing, through which the fibers are oxidized superficially.