含钇铝碳化硅陶瓷纤维的制备及性能  

Fabrication and Performance of SiC Ceramic Fibers Containing Yttrium and Aluminum

作　　者：张潇[1] 陈建军[1] 李晓鸿 张梦娜 陆俊冲 ZHANG Xiao;CHEN Jianjun;LI Xiaohong;ZHANG Mengna;LU Junchong(School of Materials Science and Engineering,Zhejiang Sci−Tech University,Hangzhou 310018,China)

机构地区：[1]浙江理工大学材料科学与工程学院,杭州310018

出　　处：《硅酸盐学报》2024年第9期2789-2799,共11页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(51872262);浙江省自然科学基金(LZ23E020003)。

摘　　要：SiC纤维中无定形的SiC_(x)O_(y)相在高温下发生分解,会导致SiC微晶的生长和性能下降,在SiC纤维中掺入异质元素可以在高温下起到烧结助剂的作用,从而提高SiC纤维的性能。采用实验室自制的聚硅碳硅烷(PSCS)与乙酰丙酮钇、乙酰丙酮铝反应制备得到含钇铝聚碳硅烷(PYACS),经过熔融纺丝、碘不熔化、高温烧成等工艺,制得含钇铝SiC陶瓷纤维。结果表明,PYACS先驱体中有效的引入了Y和Al元素,并以Si—O—Y、Si—O—Al的形式存在。采用碘不熔化实现了纤维的交联,并通过1000℃高温裂解获得非晶Si—C—O—(Y/Al)纤维,陶瓷产率为73.96%。研究了不同热处理温度(1400,1600,1900℃)对纤维形貌和结构的影响,1900℃高温热处理的Si—C—O—(Y/Al)纤维中Al和Y以Al—O—Y的形式存在,SiC结晶程度更高,SiC晶粒尺寸增大,纤维直径进一步变小,结构逐渐致密,说明高温下Al和Y的掺杂起到了烧结致密化作用。Introduction The SiC_(x)O_(y)phase in SiC fibers will decompose at high temperature,which results in the loose structure,declining mechanical performance,and lowing the high temperature resistance of the fibers.Introduction of some elements can play the role of sintering assistant at high temperature.Nearly stoichiometric polycrystalline SiC fibers can improve the oxidation resistance of fibers at high temperature.Al and Y are commonly used as sintering additives for SiC ceramics.Al and Y can form yttrium aluminum garnet(YAG)liquid phase at high temperature.The YAG liquid phase is conducive to reduce the sintering temperature and improve the densification of SiC ceramics.If the SiC fibers can form YAG phase at high temperature,the performance of SiC fibers can be improved.In this work,the both Y and Al are introduced for the fabrication of high performance SiC fibers.Methods A certain amount of polydimethylsilane(PDMS)was placed in a flask,raised to 470℃and hold for 42 h in N_(2),then cooled to room temperature,filtered to obtain yellowish viscous polysilacarbosilane(PSCS).0.4 g yttrium acetylacetone(Y(AcAc)_(3))and 0.6 g aluminum acetylacetone(Al(AcAc)_(3))were uniformly mixed with 20 g PSCS in a flask,polymerized in N_(2),and then dissolved,filtered,and distilled under vacuum to obtain polyyttrio-aluminocarbosilane(PYACS)precursor.A certain amount of PYACS precursor was added to a spinning cylinder,heated to 300℃in N_(2),for defoaming,then reduced to 240℃.Using a pressurized N_(2)(flow rate of 0.1 L/min),the melt was extruded through a single hole spinneret and the fiber was stretched and wound on a spool by a drafting device at a winding speed of 350 r/min.Curing of the fibers was carried out by exposing fibers in iodine with mass ratio of 3:5,covered with glass and placed in oven.The system was heated up to 80℃for 3 h,then cooling to room temperature.PYACS fibers were pyrolysied in N_(2) and converted into ceramic fibers at different temperature schdule,such as 20℃to 400℃with a heating rate of 150

关 键 词：碳化硅纤维 含钇铝聚碳硅烷 碘不熔化 高温烧结 

分 类 号：TQ343[化学工程—化纤工业]