热氧化法制备微米中空碳化硅陶瓷纤维管及氧化扩散模型的建立

项目名称： 热氧化法制备微米中空碳化硅陶瓷纤维管及氧化扩散模型的建立

项目编号： No.51462004

项目类型： 地区科学基金项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 黎阳

作者单位： 贵州师范大学

项目金额： 47万元

中文摘要： 中空SiC纤维在高温过滤器、微反应器、核能制氢气体分离材料、雷达波吸收材料、复合材料增强体等领域具有广泛的应用前景。采用电子束辐照氧化聚碳硅烷（PCS）先驱丝法可制备出力学性能优异的中空SiC纤维。考虑到辐射法的弊端，申请者另辟蹊径以空气为反应气氛，通过控制热氧化暴露时间与温度仅使PCS先驱丝表层氧化，并经后续中空化与陶瓷化处理成功地制备了中空SiC纤维。基于上述研究，本项目拟对氧在PCS先驱丝中氧化扩散的行为与机制进行研究，分析氧在PCS先驱丝及中空SiC纤维管壁径向上的分布规律，揭示热氧化处理温度、暴露时间、氧气分压等因素对PCS先驱丝表层氧化程度及SiC纤维管管壁厚度的影响规律，探明氧在先驱丝中氧化扩散行为机制，建立不同热氧化处理温度、暴露时间、氧气分压等条件下氧在PCS先驱丝中的氧化扩散模型，为细直径、薄管壁、低氧含量的异形中空SiC纤维及中空Si3N4纤维的研制奠定基础。

中文关键词： 热氧化；聚碳硅烷纤维；微米中空；碳化硅陶瓷纤维；扩散模型

英文摘要： Silicon carbide(SiC) hollow fiber can be used as filter,micro reactor, nuclear hydrogen gas separation materials, radar absorbing materials and composites reinforcement based on special hollow structure and properties. SiC hollow fibers with excellent mechanical properties could be prepared by processes of using electron beam irradiation oxidation polycarbosilane fibers. Considering the shortage of applications of radiation method, applicants using air as reaction atmosphere to make the oxidation take plcae only at surface by controlling the exposure time and temperature of thermal oxidation,and the follow-up processes of hollow molding and sintering were introduced, the SiC hollow fibers with the same properties were prepared by thermal oxidation method.In this project the oxidation diffusion behavior and mechanism of the oxygen in PCS precursor fibers will be investigated. The effect of thermal oxidation treatment temperature, exposure time and oxygen pressure on oxidation degree and tube wall thickness will be studied. Oxidation diffusion model of the oxygen in PCS precursor fibers will also be built by relating data. Relevant theory obtained in this project will be applicated for researching SiC and Si3N4 fibers with shaped hollow structure.

英文关键词： thermal oxidation;polycarbosilane fibers;micron hollow;silicon carbide ceramic fibers;diffusion model