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本文用透射电镜、X 射线衍射分析等方法观察和分析了辐射状中间相沥青基石墨纤维的显微结构。结果表明,中间相沥青基石墨纤维中同时存在着有序石墨和乱层石墨两种相。在有序石墨相中,石墨片层堆叠的有序程度较高,且在纵向沿纤维轴高度择优取向,在横向则基本上沿径向排列。有序石墨微晶一般呈略有弯曲的片状,并具有分枝结构,微晶在纵向沿纤维轴交错排列,而在横向则沿径向从芯部向表层不断延伸、分叉和交织。在乱层石墨相中,石墨片层堆叠的有序程度较差,且沿纤维轴的择优取向程度较低。乱层石墨相一般镶嵌在有序石墨微晶之间。此外,在某些地方还存在着严重的晶格畸变。
In this paper, the microstructure of radial mesophase pitch-based graphite fibers was observed and analyzed by transmission electron microscopy and X-ray diffraction. The results show that there are two phases of ordered graphite and turbulent graphite in mesophase pitch-based graphite fibers. In the ordered graphite phase, the graphene sheets are highly ordered and are highly preferentially oriented in the machine direction along the fiber axis and substantially radially in the transverse direction. The ordered graphite crystallites are generally slightly curved sheets and have a branched structure in which the crystallites are staggered longitudinally along the fiber axis while extending continuously from the core toward the surface in the transverse direction, diverging and interlacing. In the turbulent graphite phase, the stacking of the graphite sheets is less ordered and has a lower preferred orientation along the fiber axis. Uncharacterized graphite phase generally inlaid in ordered graphite crystallites. In addition, there are serious lattice distortion in some places.