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以沥青基炭单丝为基体,一甲基三氯硅烷为前驱体,使用静态化学气相沉积工艺,在1473K,常压环境下制备了SiC纤维。使用电子万能试验机测试了同一批次纤维的拉伸强度,结果表明其为双峰直方图分布。使用光学显微镜和扫描电子显微镜对纤维的形貌结构进行了表征。沿着反应器方向,不同区域的纤维依次表现为颗粒状、球状、平滑和倒圆锥结构。这些结构的差别导致了纤维力学强度的双峰分布。对沉积机制的分析表明,物料损耗效应和反应器两端的流场稳定性是影响纤维结构的主要因素。
Using bitumen-based carbon monofilament as matrix and monomethyltrichlorosilane as precursor, SiC fibers were prepared by static chemical vapor deposition at 1473K and atmospheric pressure. Tensile strength of the same batch of fibers was tested using an electronic universal testing machine and the results showed that it was a bimodal histogram distribution. Optical and scanning electron microscopy were used to characterize the morphology of the fibers. Along the reactor direction, different regions of the fiber followed by the performance of granular, spherical, smooth and inverted conical structure. The differences in these structures lead to a bimodal distribution of the fiber’s mechanical strength. The analysis of the deposition mechanism shows that the material loss effect and the flow field stability at both ends of the reactor are the main factors affecting the fiber structure.