【作者】 石南林； 金保宏； 贺连龙； 王玉敏； 雷家峰； 孙超；

【Author】 SHI Nanlin JIN Baohong He Lianlong WANG Yumin LEI Jiafeng SUN Chao (Institute of metal research,Chinese Academy of Sciences,Shenyang,110016)

【机构】 中国科学院金属研究所；

【摘要】 对国产高性能CVD SiC(W芯)纤维的微观结构进行了观察。结果表明,SiC纤维晶粒由纳米尺度的等轴晶、棒状晶纳米晶区层和的亚微米尺度柱状晶区层组成,并呈梯度长大,其取向度逐渐提高。纤维晶粒细化以及晶粒沿纤维径向梯度长大减少了纤维缺陷,同时也减小了缺陷尺寸、缓解了纤维内部生长应力,因而改善了纤维的力学性能。更多还原

【Abstract】 The microstructure of high performance CVD SiC(W core) fiber has been observed using scanning electron microscopy(SEM) and transmission electron microscopy(TEM).The result indicated that the SiC layer consists ofβ-SiC crystallites with a strong(111) plane orientation.There is a quantity of non-crystalline phase in the SiC layer nearby the W core region.SiC grains varied from small equiaxed grains,fine clubbed grains to coarse columnar grains in their morphologies,and the orientations get more order from the W core to the surface regions of fiber.It was also found a lot of extensive dislocation,stacking faults and twins in the SiC crystals.The structure of carbon surface coating mainly consists of turbostratic carbon.The release of the residul stress of the fiber and the grain refinement and gradual distribution in the fiber is the main reason for improvement of tensile strenth of the SiC fiber.更多还原