New strategy for impedance measurement of surface oxidation characteristic in ceramic fiber by controlling aspect ratio

Abstract

Silicon carbide fibers (SiCf) are promising materials for high-temperature applications, because of their excellent thermal and mechanical properties. Due to the inevitable oxidation of SiCf used at high-temperature, the surface and interfacial properties of SiCf can be changed. Impedance analysis is necessary to confirm the useful infor-mation for various properties. However, since single SiCf has a long length and a very small cross-section area, its capacitance is so small that impedance analysis is almost impossible. In this study, an in-situ analysis tool that can estimate the impedance of SiCf to confirm the resistance elements is proposed using bundled fiber specimens. It is confirmed that it is possible to measure the impedance of the SiCf under high-temperature and oxidation atmospheres by controlling the aspect ratio of the specimen. This tool provides a new pathway that can be applied in various systems by investigating the electrical properties according to the oxidation behavior.