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以沥青基碳单丝为基体,一甲基三氯硅烷为碳化硅前驱体,使用通电加热的冷壁CVD工艺,温度在1 473～1 773 K,制备了碳芯SiC纤维。采用扫描电子显微镜和拉曼光谱对纤维的表面形貌及结构进行了表征,研究了沉积温度对其结构的影响。结果表明,SiC涂层为β-SiC晶型。沉积温度的升高引起了沉积速率的增加以及SiC涂层晶粒尺寸的长大。同时,导致碳芯中心区域发生结构重排,引起了该区域取向度的提高以及晶粒尺寸的减小。
Using pitch-based carbon monofilament as matrix, monomethyltrichlorosilane as silicon carbide precursor, carbon-core SiC fibers were prepared by cold-wall CVD with electric heating at a temperature of 1473 ~ 1773K. The morphology and structure of the fibers were characterized by scanning electron microscopy and Raman spectroscopy. The effects of deposition temperature on the structure of the fibers were investigated. The results show that the SiC coating is β-SiC crystal form. The increase of deposition temperature caused the increase of deposition rate and the growth of SiC coating grain size. At the same time, structural rearrangement in the central region of the carbon core occurs, which leads to the increase of the orientation degree and the decrease of the grain size.