γ辐照聚碳硅烷先驱丝热解制备氮化硅陶瓷纤维及性能  

Preparation and Properties of Silicon Nitride Fibers Synthesis From γ-ray Irradiation Curing of Polycarbosilane Precursor Fibers

作　　者：黎阳[1,2] 高家诚[1] 

机构地区：[1]重庆大学材料科学与工程学院,重庆400045 [2]贵州师范大学材料与建筑工程学院,贵阳550014

出　　处：《硅酸盐学报》2013年第10期1318-1322,共5页Journal of The Chinese Ceramic Society

基　　金：贵州省自然科学基金项目(2010)2008资助

摘　　要：在空气中采用γ射线辐照不熔化处理聚碳硅烷先驱丝,辐照先驱丝经NH3热解氨化、N2高温处理工序制备了Si3N4陶瓷纤维。利用红外光谱仪、碳硫分析仪、氮氧联测仪、X射线衍射仪、单纤维强度测试仪和扫描电子显微镜研究了辐照先驱丝的氨化过程以及最终制备Si3N4陶瓷纤维的性能。结果表明:辐照先驱丝在NH3中热解氨化时,随着氨化温度的升高,氨化纤维中碳含量逐渐降低、氮含量逐渐升高,在700℃时氨化纤维中有大量的Si-NH-Si和Si-NH2结构单元生成,经1000℃氨化后,氨化纤维中碳与氮含量分别为0.23%和28.75%;氨化纤维在N2中热处理时,随处理温度的升高,抗拉强度先升高后降低,在1200℃取得最大值为1.57GPa,当处理温度达1400℃时,Si3N4纤维由无定型结构长大转变为α-Si3N4晶型结构,抗拉强度仅为0.56GPa。Polycarbosilane （PCS） precursor fibers were cured via γ-ray irradiation in air. Silicon nitride ceramic fibers were obtained by the ammoniation process of the irradiated fibers in ammonia and subsequent high temperature treatment of the ammoniated fibers in nitrogen. The ammoniation process of the irradiated fibers and the properties of the Si3N4 ceramic fibers were investigated by in- frared spectrometry, carbon sulfur analysis, oxygen and nitrogen combustion analysis, X-ray diffraction, single fiber strength exami- nation and scanning electron microscopy, respectively. The results show that the carbon content decreases and the nitrogen content increases with increasing ammoniation temperature. The structures of Si-NH-Si and Si-NH2 are formed in the ammoniated fibers at 700 ℃. When the ammoniation temperature is 1 000 ~C, the carbon and nitrogen contents in the ammoniated fibers are 0.23% and 28.75%, respectively, the tensile strength first increases and then decreases with increasing the heat treated temperature when treating the ammoniated fibers heat in nitrogen. The tensile strength has the maximum value of 1.57 GPa at 1 200℃. The crystal structure transforms into a-Si3N4 from the amorphous state and the tensile strength is 0.56 GPa when the heat treated temperature is 1 400 ℃.

关 键 词：聚碳硅烷 Γ射线 氨气 氮化硅陶瓷纤维 

分 类 号：TQ174[化学工程—陶瓷工业]