电化学表面处理对SiC纤维的强化作用

REINFORCEMENT MECHANISM OF CVD SiC FIBER BY SiO2 SURFACE FILM

采用ＳＥＭ分析了用电化学表面处理方法得到的高强度ＳｉＣ纤维表面形貌和断口的结构 讨 论了表面氧化股的形成对用 ＣＶＤ法制备的

Morphology of the surface and fracture of the high-tensile-strength SiC fiber after electrochemical treatment was analyzed in this paper. During the process of anodic oxidation, SiO2 particles formed in some active regions on the Sic fiber surface at first, then connected together becoming a compact surface layer. Formation of the SiO2 layer smoothened the surface morphology, and lessened the number of surface defects, and also alleviated the locally concentrating of tension. On the other hand, the surface took on compression instead of the inherent slight tension after electrochemical treatment by the differential on Mole volume between SiO2 and SiC, and the occurring and enlarging of the micro-cracks on the surface were seriously restrained. According to the comparison between the measuring values and the calculating results, it is greatly possible that compression is the main reason for the reinforcement of SiC fibers.