C/C复合材料石墨化度的喇曼光谱表征

Charaterization of Graphitization Degree of C/C Composites by Laser Raman Microspectroscopy

采用显微激光喇曼光谱及XRD测量、表征了C/C复合材料中炭纤维、沥青炭及CVD热解炭经不同温度石墨化处理后的结构参数.结果表明:在3种炭材料的喇曼图谱上都有2个散射强度峰-D峰和G峰,峰位分别位于喇曼位移约1333及1584cm-1处,随石墨化处理温度改变,2峰峰位没有变化,但2峰相对强度却发生变化.将D峰相对于G峰的强度R的倒数R-1与XRD法得到的石墨化度g比照,发现2者存在一一对应关系,符合公式:g=1-exp[-2.11(R-1-0.34)].

The structural parameters of carbon fiber, pitch-derived carbon and pyrolytic carbon in C/C composites were charaterized by laser Raman microspectroscopy and XRD. In Raman spectra of these carbons, two bands named D and G were observed near 1336.73 cm(-1) and 1581.00 cm(-1) respectively, the peak positions do not but the relative intensities of the two bands change with heat treatment temperatures. The relationship between the XRD data of graphitization degree g and R(-1) where R is the relative intensity of band D to band G was plotted, the result shows that g increases with the increase of R(-1), but the gradient of the R(-1)-g curve decreases and gradually tends to zero with the increase of R(-1), and their relation can be written into the following equation: g=1-e(-2.11(1/R-0.34)). The foundation of the correlation between R(-1) and g makes it possible to analyze the local distribution of graphitization degree in C/C composites.