单向C/C复合材料中碳纤维和热解碳微结构的XRD法分析  

Analyses of Microstructures of Carbon Fibers and Pyrocarbon in Unidirectional Composites by XRD Method

作　　者：李同起[1] 胡子君[1] 许正辉[1] 杨晓光[1] 

机构地区：[1]航天材料及工艺研究所先进功能复合材料技术国防科技重点实验室,北京100076

出　　处：《宇航材料工艺》2009年第5期74-77,共4页Aerospace Materials & Technology

基　　金：国家973课题(2006CB600907);国防973课题(6138002);国防技术基础项目(T032007B002)

摘　　要：文摘为了研究单向C/C复合材料中碳纤维和热解碳的微结构特征,采用X射线衍射仪对T300碳纤维/热解碳单向复合材料进行了表征,并通过XRD谱峰的分峰处理和复合材料衍射峰与碳纤维衍射峰的峰减处理分析了碳纤维和热解碳的微结构特征。研究发现,分峰处理可以有效地将复合材料衍射峰中反映碳纤维和热解碳结构的衍射信号分离,结合对它们衍射峰的特征参数分别进行分析,可以得到碳纤维和热解碳的微晶参数。通过对比复合材料中碳纤维与自由态碳纤维的微晶参数可以发现,由于复合材料中碳纤维经受应力石墨化作用,复合态碳纤维的结构比自由态碳纤维更易于向类石墨结构发育;峰减处理法对于分析002衍射峰比较有效,获得的热解碳的d002和Lc与分峰处理获得的数据相当,但由于10峰受背景峰信号的影响较大,峰减处理法对10峰的分析存在较大误差,获得的La与分峰处理获得的数据偏差较大。In order to investigate the microstructures of carbon fiber and pyrocarbon in composites, X - ray diffraction method was used to characterize the unidirectional C/C composites with T300 carbon fiber as the reinforcement. With the fitting and subtraction of the obtained diffraction peaks, the carbon fibers and pyrocarbons in composites were analyzed respectively. It is found that the peak fitting method can effectively extract the structural information of carbon fibers and pyroearbons from the composite diffraction peaks. Combined with the analyses of the fitted peak features, the microcrystal parameters can be obtained for carbon fibers and pyrocarbons respectively. Compared with the microstruetures of free-state carbon fibers, the composite carbon fibers tend to form carbon with more graphite-like structures during high temperature treatment due to the stress graphitization in composites. The subtraction method by deducting the diffraction peaks of free-state carbon fibers from those of composite carbon fibers can be used to analyze the 002 peaks and the obtained d002 and Lc are analogous to those derived from the fitting method. For the influence of background signal on 10 peak, the subtraction method is not applicable to obtain crystal size of La.

关 键 词：T300碳纤维 热解碳 微结构 XRD 分峰处理 峰减处理 

分 类 号：TQ342.742[化学工程—化纤工业] TB332[一般工业技术—材料科学与工程]