γ射线辐照不熔化法制备碳化硅纤维及其性能  

Preparation and Properties of Silicon Carbide Fibers Prepared by γ-Ray Irradiation Curing Method

作　　者：黎阳[1] 许云书[2] 

机构地区：[1]贵州师范大学材料与建筑工程学院,贵阳550014 [2]中国工程物理研究院核物理与化学研究所,四川绵阳621900

出　　处：《硅酸盐学报》2011年第11期1719-1723,共5页Journal of The Chinese Ceramic Society

基　　金：贵州省科学技术基金(2010)2008;中国工程物理研究院科学技术基金重大项目(2004Z0502)资助

摘　　要：在空气中用γ射线辐照聚碳硅烷(polycarbosilane,PCS)先驱丝,利用红外光谱分析、凝胶含量测定、热重分析、氧含量测定和抗拉强度测试等手段研究了辐照前后PCS先驱丝化学结构、凝胶含量、热分解特性以及烧成SiC纤维的微观形貌、氧含量、抗拉强度和高温性能。结果表明:经γ射线辐照处理的PCS先驱丝通过形成Si—O—Si和Si—C—Si桥联结构实现不熔化,其凝胶点剂量为1.2 MGy,凝胶化剂量为3.0 MGy;辐照后先驱丝的陶瓷产率迅速提高,吸收剂量为0.5 MGy的先驱丝陶瓷产率达83.2%,随吸收剂量增加陶瓷产率增加趋于缓慢。吸收剂量为3.0 MGy时烧成的SiC纤维氧含量达15.1%,抗拉强度达1.8 GPa。该SiC纤维在高温热处理时,在1 200℃开始发生破坏,1 400℃时基本丧失力学性能,纤维开裂严重。Polycarbosilane（PCS） precursor fibers were prepared by γ-ray irradiation curing in air.The chemical structure,gel content and thermal decomposition characteristics of the PCS fibers before and after irradiation curing and the performance of the sintered SiC fibers were investigated by infrared spectrometry,thermogravimetry,gel content,oxygen content and tensile strength.The results show that the irradiated PCS fibers become infusible due to the formation of bridge structures of Si—O—Si and Si—C—Si.The dose of gel point and gelling of the PCS were 1.2 MGy and 3.0 MGy,respectively.The ceramic yield of the PCS fibers increased rapidly after irradiation.When the absorbed dose was 0.5 MGy,the ceramics yield could reach 83.2%.The ceramic yield of SiC fibers in-creased with the increase of absorbed dose.The oxygen content and tensile strength of fibers with the absorbed dose of 3.0 MGy were 15.1% and 1.8 GPa,respectively.The SiC fibers became destruct when heat treated at 1 200 ℃.After heat treated at 1 400 ℃,the SiC fibers reduced the mechanical properties and appeared the more cracks

关 键 词：聚碳硅烷 Γ射线 碳化硅纤维 高温性能 

分 类 号：TQ174[化学工程—陶瓷工业] O631.3[化学工程—硅酸盐工业]