中文摘要：

采用CVI方法制备出了具有热解碳界面层的碳纤维增强Si-C-N陶瓷基复合材料（C/PyC/Si-C-N）和无界面层的碳纤维增强Si-C-N陶瓷基复合材料（C/Si-C-N）。用热膨胀仪分别测试了C/PyC/Si-C-N和C/Si-C-N的热膨胀性能,研究了碳界面对复合材料热膨胀性能的影响。研究结果表明：在25~1200℃范围内,C/PyC/Si-C-N复合材料的平均热膨胀系数为0.638×10-6 K-1,线膨胀率为0.0752%;在780℃以上,碳界面的存在使碳纤维增强SiC-N基复合材料的热膨胀系数降低,在780℃以下时则对复合材料的热膨胀系数基本无影响。

英文摘要：

Carbon fiber reinforced Si-C-N matrix composite with a pyrolytic carbon（PyC）interlayer（C/PyC/Si-C-N）and the composite without interlayer（C/Si-C-N）was fabricated by chemical vapor infiltration processing.The thermal expansion of these composites was measured by using thermal dilatometer and laser heat conductometer,and the influence of PyC interlayer on thermal expansion behavior of the composites was investigated.The results indicated that the average coefficient of thermal expansion and line expansion rate of C/PyC/Si-C-N between 25-1200 ℃were 0.638×10-6 K-1 and 0.0752%,respectively.The PyC interlayer could reduce the coefficient of thermal expansion（CTE）of the composite above 780 ℃,while hardly affected CTE below 780 ℃.