PyC层对SiC纤维束及MiniSiC/SiC复合材料拉伸性能和强度分布的影响  

Effect of PyC Layer on Tensile Properties and Strength Distribution of SiC Fiber Bundles and Mini SiC/SiC Composites

作　　者：孟志新[1] 成来飞[1] 刘善华[1] 李良军[1] 王操[1] 张立同[1] 

机构地区：[1]西北工业大学超高温结构复合材料国家重点实验室,西安710072

出　　处：《材料导报》2011年第16期5-7,共3页Materials Reports

基　　金：国家杰出青年科学基金(50425208);重大国际合作研究项目(NSFC50820145202)

摘　　要：采用等温等压化学气相浸渗法(ICVI),对原始的SiC纤维束和沉积有PyC层的SiC纤维束浸渗SiC基体,制备了纤维束复合材料SiC/SiC(Mini SiC/SiC)。分析了SiC纤维束和Mini SiC/SiC复合材料的拉伸性能,同时利用两参数Weibull分布研究了强度分布。结果表明,PyC层具有修复纤维表面缺陷的作用,SiC纤维束沉积PyC层后,纤维表面光滑而致密,表面缺陷减少,其拉伸强度、延伸率和Weibull模数分别比原始SiC纤维束提高了25%、12%和288%;且由其增强复合材料的拉伸强度、延伸率和Weibull模数分别比由原始SiC纤维束增强复合材料提高了103%、83%和340%。PyC界面层对SiC纤维表面缺陷的修复作用和对SiC纤维的保护作用以及降低复合材料裂纹敏感性的作用提高了Mini SiC/SiC复合材料的拉伸性能和Weibull模数。The Mini SiC/SiC composites, reinforced by the as-received SiC fiber bundle and the SiC fiber bundle with PyC layer, respectively, were fabricated by isothermal and isobaric chemical vapor infiltration（ICVI）. The tensile properties of the fiber bundles and minicomposits were analyzed and their strength distribution was also studied by means of two-parameter Weibull distribution method. The results show that PyC layer has the function of repairing defects on the fiber surfaces. After the deposition of PyC layer on the SiC fiber bundle, the surfaces of fibers become smooth and dense, and the defects on the fiber surfaces decrease. Meanwhile, its tensile stregnth, elongation percenta- ge and Weibull modulus are 25%, 12% and 288% higher than those of the as-received SiC fiber bundle, respectively. Further more, the tensile stregnth, elongation percentage and Weibull modulus of the minicomposite reinforced by it are 103%, 83% and 340% higher than the minicomposite reinforced by the as-received SiC fiber bundle. The tensile properties and Weibull modulus of Mini SiC/SiC composite are increased by the functions of repairing defects on the SiC fiber surfaces, proctecting SiC fibers and reducing crack-sensitivity of the minieomposite all from the PyC layer.

关 键 词：纤维束复合材料 PyC层 拉伸性能 强度分布 化学气相浸渗 

分 类 号：TB332[一般工业技术—材料科学与工程] TQ174[化学工程—陶瓷工业]