中文摘要：

以六甲基二硅氮烷为先驱体，采用电热裂解化学气相沉积技术制备了以热解碳为界面的连续碳纤维增强SiCN陶瓷基复合材料（C／SiCN），并在不同温度和时间下进行了真空热处理。用扫描电镜、透射电镜、高分辨透射电镜、X衍射仪和光电分析天平分别进行微观观察、相变分析和质量测量。结果表明：热处理温度对基体晶化程度的影响要比增加热处理时间的影响更明显；非晶SiCN基体经1100℃热处理30h后已有微量B．SiC晶粒产生；在1100℃，30h；1300℃，30h；1500℃，30h和1700℃，2h热处理后，部分SiCN转变为SiC，没有发现Si3N4；1700℃热处理2h后，晶粒间的非晶SiCN内出现层状石墨；1900℃热处理0．5h后，SiCN基体几乎全部晶化，并明显出现Si3N4晶体；在1100℃到1300℃真空热处理30h后，质量损失主要是H^-的损失：在1500℃到1900℃处理后，除了H^-损失之外，还有部分N^-损失。

英文摘要：

Carbon fiber reinforced silicon carbonitride matrix composite （C/SiCN） with a pyrolytic carbon interface was prepared by electrothermal pyrolysis chemical vapor infiltration using hexamethyldisilazane as raw material. The composite was heat treated at different temperatures for different time periods in vacuum. Scanning electron microscopy, transmission electron microscopy, high resolution transmission electron microscopy, X-ray diffraction and photoelectric analytical balance were used to characterize the microstructure, phase transformation, and mass change, respectively. The results indicate that the effect of the heat treatment temperature on the crystallization degree of matrix in the composite is greater than that of the holding time. After heat treatment at 1 100 ℃ for 30 h, a few 13-SIC crystallites were observed in the amorphous SiCN. The main crystallites in the matrix are SiC after heat treatment at 1 100 ℃ for 30h, 1 300℃ for 30h, 1 500 ℃ for 30h or 1 700℃ for 2h, and no Si3N4 was found in the composites after heat treatment. Some turbostratic carbon was found in the amorphous SiCN between crystallites after heat treatment at 1 700 ℃ for 2 h. Almost the entire matrix was crystallized after heat treatment at 1 900℃ for 0.5 h containing Si3N4 that could be easily found. The mass loss at 1 100 and 1 300 ℃ was caused by the loss of hydrogen, and some nitrogen was also lost in addition to hydrogen between 1 500 and 1 900℃.