以3种典型碳纤维为研究对象，通过碳纤维断面形貌的扫描电镜分析，采用Photoshop对纤维截面特征进行有效提取并由Matlab编写程序，获得了碳纤维表面沟槽深度、宽度、个数等参数的统计信息，据此进一步计算了圆形度、沟槽深宽比、表面不规整度以及沟槽密集程度等物理量，建立了碳纤维表面物理沟槽结构的定量表征方法。在此基础上研究了原丝制备过程中的凝固环境对碳纤维表面物理结构的影响，并发现：当凝固浴温度由25℃升高至45℃时，碳纤维表面的沟槽深度及宽度均会逐渐减小，深宽比降低，沟槽形状逐渐趋于平缓，同时碳纤维的表面不规整度减小了约7.5%，而沟槽密集程度增加了约50%。采用上述具有不同表面物理结构特征的碳纤维作增强体制备复合材料，微滴脱粘测试结果表明：碳纤维复合材料的界面剪切强度（IFSS）随纤维表面的沟槽尺寸、沟槽深宽比及表面不规整度的增大而逐渐提高。

The technique of quantitative characterization for the physical structure of the surface on PAN-based carbon fiber filaments was established through analyzing the cross sectional morphology which was obtained by scanning electron microscopic (SEM), followed by the image processing with Photoshop software and self-written Matlab program. The parameters such as the width, depth, and the number of surface groove structure were obtained by statistic calculation. Then the circularity, ratio of depth to width, density of groove structure along circle direction, and irregularity were also calculated to characterize the physical structure systematically. Furthermore, the groove structure of carbon fiber was regulated and controlled by adjusting the coagulation environment during the spinning process of PAN precursor, and it is found that the depth and width of groove structure on the surface of carbon fiber are decreased gradually, the shape of grooves also tends to flatten due to the decreased ratio of depth to width, the irregularity is decreased by about 7.5%, while the density of groove structure is increased by about 50% when the temperature of coagulation bath is increased from 25℃ to 45℃. The above carbon fibers with different surface physical structures were used as reinforcements to prepare composites, the results of microdroplet debonding test indicate that the interfacial shear strength (IFSS) of composites is increased with the increasing of groove size and aspect ratio, as well as the surface irregularity of carbon fibers.