Gan Yuanfeng, Wang Xiaozhou, Wang Jun, Wang Hao
Science and Technology on Advanced Ceramic Fibres and Composites Laboratory, National University of Defense Technology Changsha 410073 People's Republic of China
RSC Adv. 2018 May 14;8(31):17453-17461. doi: 10.1039/c8ra01816b. eCollection 2018 May 9.
Near-stoichiometric SiC fibres (CVC-S fibres) were successfully prepared by pyrolysing chemical-vapour-cured polycarbosilane fibres under hydrogen and subsequent heat treatment in inert atmosphere at 1500 °C. The composition and properties of the obtained fibres were determined by Auger electron spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, tensile strength testing, and X-ray diffraction analysis. The results reveal that the CVC-S fibres with C/Si of 1.06 and O of 1.11 wt% have high tensile strength (2.6 GPa), high tensile modulus (321 GPa), and a highly crystalline structure (crystallite size, ∼14 nm.) In addition, the high-temperature behaviour of the CVC-S fibre was also investigated heat treatment in argon and air at different temperatures. In particular, the fibres retain ∼2.2 GPa of their original strength after heating at 1600 °C for 1 h under argon. When argon was replaced by air, the tensile strength of the fibres could still be maintained at ∼1.1 GPa after annealing at 1400 °C. The more economical and practical approach along with the excellent performance of the obtained fibres render the CVC-S fibres promising materials for high-temperature applications.
通过在氢气氛围下热解化学气相固化的聚碳硅烷纤维，并随后在惰性气氛中于1500℃进行热处理，成功制备了近化学计量比的SiC纤维（CVC-S纤维）。通过俄歇电子能谱、X射线光电子能谱、扫描电子显微镜、透射电子显微镜、拉伸强度测试和X射线衍射分析来确定所得纤维的组成和性能。结果表明，C/Si比为1.06且氧含量为1.11 wt%的CVC-S纤维具有高拉伸强度（2.6 GPa）、高拉伸模量（321 GPa）和高度结晶的结构（微晶尺寸约为14 nm）。此外，还研究了CVC-S纤维在不同温度下于氩气和空气中的高温行为。特别是，该纤维在氩气中于1600℃加热1 h后仍保留约2.2 GPa的原始强度。当将氩气换成空气时，在1400℃退火后纤维的拉伸强度仍可保持在约1.1 GPa。所获得的纤维具有更经济实用的方法以及优异的性能，使其成为高温应用中有前景的材料。
