新型连续硅铪氧碳陶瓷纤维的可控制备及其高温性能的研究

项目名称： 新型连续硅铪氧碳陶瓷纤维的可控制备及其高温性能的研究

项目编号： No.51202157

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 无机非金属材料学科

项目作者： 苏冬

作者单位： 天津大学

项目金额： 25万元

中文摘要： 陶瓷纤维具有轻质、高强、耐高温等优异的物理、力学和高温性能，是制备高性能复合材料的重要材料，在航空航天、能源和环境等诸多国防和民用领域有重要应用。溶胶凝胶法具有制备温度低、结构和组分可调等优点，但目前获得的纤维存在耐高温性不足和纺丝连续性差的问题。本项目提出利用铪酸酯和硅氧烷的溶胶凝胶反应，控制反应，经纺丝合成出连续的含铪聚硅氧烷凝胶纤维，利用热解过程中铪与纤维中的氧、碳和硅原子等反应形成氧化铪、碳化铪和硅酸铪等高熔点相，获得耐高温的硅铪氧碳陶瓷纤维。通过反应控制，解决反应过程中铪酸酯和硅氧烷不均匀缩聚引起的分相和团聚问题，进而研究溶胶的反应、结构和可纺性的关系，获得连续纺丝；同时，研究陶瓷纤维的热解行为、结构、组成和性能，重点研究热解过程中铪的键连方式和结构转变，分析铪的结构与纤维高温性能的关系，在此基础上实现硅铪氧碳纤维的结构设计与调控，获得连续的具有优异耐高温性能的陶瓷纤维。

中文关键词： 硅基陶瓷纤维；溶胶凝胶；硅氧碳陶瓷；金属氧化物；耐高温性能

英文摘要： Ceramic fibers have low weight, high strength, high modulus and resist to high temperatures and oxidations which are used as the important materials for the fabrication of high performance composites. These superior physical, mechanical and thermostability properties offer them a wide range of applications in military and civilian fields, such as aerospace, mechanical engineering, chemical engineering, energy and environment. Therefore, development of novel high-performance continuous ceramic fiber has important scientific significance and application value. Sol-gel process is an important route to fabrication of ceramic fibers because of its mild reactions, adjustable compositions and lower fiber formation temperatures, but until now fibers obtained in this way have the defects of poor thermostability and poor continuity spinning. This project proposes fabrication of novel silicon hafnium oxycarbide continuous ceramic fibers by the sol-gel reaction of hafnium and silicon alkoxides through spinning and pyrolysis under the controlled conditions. During the pyrolysis, the hafnia could react with the oxygen, carbon and silicon of the SiOC to form high melting point phases (such as, HfO2, HfC and HfSiO4) to increase the structural stability and oxidation resistance of the fiber. In this project, the spinnability of

英文关键词： silicon-based ceramic fibers；sol-gel；silicon oxycarbide ceramics；metal oxides；high-temperature property