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在场发射扫描电子显微镜（ＦＥ－ＳＥＭ）下观察了圆形、中空、条形和Ｙ－形中间相沥青炭纤维的横断面结构。用流变学理论分析了纺丝过程中几种炭纤维结构的形成，提出中空纤维纺制时沥青流体的最大流速线在喷丝孔中心线的内侧，并根据中空炭纤维横断面的显微照片对此加以证实，用催化缩聚中 间相沥青制备的条形炭纤维显示出的特殊弧形对称结构，起因于中间相沥青的流变性质和条形喷丝孔的形状设计，非圆形中间相沥青炭纤维趋向于以线形为中心的放射状横断面结构，因而在热处理过程中能避免应力集中和裂纹产生，有利于提高炭纤维的抗压强度。
The cross-sectional structures of circular, hollow, bar and Y-shaped mesophase pitch carbon fibers were observed under a field emission scanning electron microscope (FE-SEM). The rheological theory was used to analyze the formation of several carbon fiber structures during the spinning process. The maximum flow velocity of the bitumen fluid in the hollow fiber spinning process was found on the inner side of the centerline of the spinneret. According to the microstructure of the hollow carbon fiber, The photo confirms that the special arcuate symmetry structure of bar-like carbon fibers prepared by catalytic polycondensation of mesophase pitch results from the rheological properties of mesophase pitch and the shape design of the spinneret holes, Pitch-like carbon fibers tend to have radial cross-sectional structures centering on the linear shape. Therefore, stress concentration and cracks can be avoided during heat treatment, which is favorable for improving the compressive strength of the carbon fibers.