先驱体转化法制备含异质元素碳化硅纤维的研究进展

Research progress in preparation of polymer-derived SiC fibers containing hetero elements

连续SiC纤维及其复合材料以其优异的耐高温、抗氧化以及机械性能在航空航天以及核领域有着广泛的应用前景。先驱体转化法已成为制备连续SiC纤维最重要的方法。特定异质元素的引入可以有效改善SiC纤维的性能。本文结合我们团队近40年在先驱体转化法制备高性能SiC纤维领域的相关工作,首先综述了异质元素的引入方式,主要包括物理共混和化学改性;从提高先驱体的陶瓷产率、促进纤维烧结致密化,提高SiC纤维的耐高温性能以及拓展SiC纤维的功能化应用等方面阐述了异质元素的作用和机理;然后分别介绍了国内外含Ti、Al、Zr、Fe、B以及难熔金属(Hf、Ta、Nb)等含异质元素SiC纤维的组成、结构与性能以及发展现状,最后对陶瓷先驱体体系构建、异质元素种类含量与纤维性能构效关系研究、以及纤维工程化应用等研究方向进行了展望。

Continuous SiC fibers reinforced SiC ceramic matrix composites have wide applications in the aerospace and nuclear fields owing to their excellent high-temperature resistance,good oxidation resistance and mechanical properties.The precursor-derived method has been the most important method for preparing continuous SiC fibers.The introduction of specific hetero elements could effectively improve properties of SiC fibers.Based on the research work on precursor-derived SiC fibers of high performance carried out by our group in the past forty years,this review firstly summarizes the addition methods of hetero elements,mainly including physical blending or chemical modification methods;The role and mechanism of hetero elements have been elucidated from several aspects:increasing the ceramic yield of the precursor,facilitating densification during sintering of the precursor-derived SiC fibers,improving high-temperature resistance of the final SiC fibers,and generating functions of SiC fibers;The composition,microstructure,properties,and developmental status of SiC fibers containing hetero elements,such as Ti,Al,Zr,Fe,B,as well as refractory metals(Hf,Ta,Nb),have been introduced.Furthermore,future research in the development of precursor systems,quantitative study of the relationship between the types and contents of hetero elements and properties of derived fibers,as well as engineering applications of the precursor-derived SiC fibers,has been prospected.