用H－800分析型透射电子显微镜研究碳纤维的微细结构

Study on Microstructure of Carbon Fibersusing A H-800 Analytical Transmission Electron Microscope

本文以研究碳纤维微细结构为目的，讨论了在不具备高分辨型透射电子显微镜的条件下，利用分析型透射电子显微镜拍摄碳纤维碎片和切片的晶格条纹像的方法和条件。采用倾斜电子束的方法，根据相应的相位衬度传递特性曲线，针对不同结构尺寸的碳纤维确定适当的离焦量，可拍摄出碳纤维的晶格条纹像。由碳纤维纵向切片的高分辨像和电子衍射花样可以看出，碳纤维的晶面间距约为０．３４ｎｍ，纵向结构取向平行于纤维轴。碳纤维的模量随着热处理温度的升高而增加，其晶面间距减少，条纹变直、变长，趋于规整。

This paper,with the purpose of studying the micro-structure of carbon fibers from fragments and longitudi-nal sections,discusses the methods of using an analytical TEM with high spherical aberration coefficient(e.g.Cs=3.0mm) when an ultra high resolution TEM is not available.The lattice -fringe images can be obtained byusing the tilted-beam and appropriate defocusing amount which is determined by the phase contrast transfer cur-ve.The 002 graphite layer plane space is about 0.34nm.The orientation of crystallite is parallel to the fiber axisand the Young’s modulus is related to the heat-treament temperature.The graphite layer phanes of fiber withhigher heat-treatment temperature is better oriented than those of lower temperature specimen.