C/C复合材料结构显微激光喇曼光谱研究

采用显微激光喇曼光谱,以增强体为薄毡叠层、基体分别为粗糙层及光滑层结构热解炭的两种C/C复合材料为研究对象,分析、表征了两种材料炭结构的微观分布特征及其在石墨化过程中的变化状况。结果表明,不仅复合材料中不同组元,而且同一组元不同部位石墨微晶的完整度不同。在石墨化过程中,各自的石墨化进程及可石墨化能力存在差异:炭纤维体积含量较高的炭布层中的热解炭,与网胎层中的热解炭相比,石墨微晶的完整度较好,石墨化进程较快;在炭纤维体积含量较低的网胎层中,炭纤维及热解炭在其界面部位的石墨化进程较快;粗糙层结构热解炭比光滑层结构热解炭容易石墨化。借助激光喇曼光谱微区分析手段,有可能实现对复合材料中石墨化程度微观分布状态的调整和控制。

LASER RAMAN MICROSPECTROSCOPY STUDY ON MICROSTRUCTURE OF C/C COMPOSITES

The local distributions of the carbon structure and their changes with HTT of two kinds of C/C composites were analyzed and characterized by using laser Raman microspectroscopy. The reinforcement of the two composites is laminated carbon felt, and the matrix of the two composites consists exclusively of RL (Rough Layer) or SL (Smooth Layer) pyrolytic carbon respectively. Experimental results show the carbon crystal structure and structural change with HTT are different: not only between different elements in composite but also between different locations in the same element. The pyrolytic carbon in the carbon cloth layer with higher volume content of CF has a higher graphitization degree than the pyrolytic carbon in the mat layer. The graphitization degrees of the locations near the interface between CF and pyrolytic carbon in pyrolitic carbon or CF increase with HTT more rapidly than those far away from the interface. RL pyrolytic carbon is more graphitizable than SL pyrolytic carbon. The results indicate that it is possible to adjust and control the local distribution of carbon structure of C/C composites by means of laser Raman microspectroscopy.