ZrB_2/SiC前驱体的制备、表征及裂解行为  

Synthesis,Characterization and Pyrolysis Behavior of ZrB_2/SiC Precursor

作　　者：葛凯凯[1,2] 邱文丰[1] 韩伟健[1] 叶丽[1] 赵爱军[1] 赵彤[1] 

机构地区：[1]中国科学院化学研究所高技术材料实验室,北京100190 [2]中国科学院大学,北京100049

出　　处：《高等学校化学学报》2014年第9期2050-2054,共5页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:21104090);中国科学院化学研究所培育项目(批准号:CMS-PY-201217)资助~~

摘　　要：以聚锆氧烷为锆源,聚硼硅氮烷兼作硼源、硅源和碳源,通过共混得到ZrB2/SiC液相前驱体,该前驱体经高温裂解得到ZrB2/SiC复相陶瓷.对ZrB2/SiC前驱体的裂解行为、陶瓷产物结构及微观形貌进行了表征.结果表明, ZrB2/SiC前驱体经1400℃裂解后保持无定形状态,1500℃处理后析出t-ZrO2晶体,1600℃时体系发生碳热还原反应生成ZrC,同时析出SiC晶体,1700℃时生成ZrB2,最终陶瓷产物晶相组成为ZrB2/SiC.在1500~2000℃范围内,随着处理温度的升高,陶瓷由致密结构变为多孔结构,最终陶瓷产物由尺寸为100~300 nm的纳米颗粒堆积而成,各元素分布均匀.A novel liquid ZrB2/SiC precursor was prepared by the blend of polyzirconoxane and polyborosi-lazane, which were used as zirconium, silicon, boron and carbon source. The precursor was transformed into ZrB2/SiC ceramic during the pyrolysis, and its pyrolytic behavior, phase composition and microstructure were studied by TGA, XRD and SEM-EDX. The results indicated that the ceramic sample remained amorphous un-til t-ZrO2 initially generated at 1500 ℃. Heating to 1600 ℃ led to the formation of ZrC via carbothermal re-duction . Further heating to 1700℃ led to the formation of ZrB2 . During heat treatments, the compact ceramic sample became porous due to formation of CO and NO. The ceramic powder with particle size of 100-300 nm consisted of high crystalline degree ZrB2 and SiC phases, and all the elements were well distributed in ceramic powders.

关 键 词：液相前驱体 裂解 碳热还原 ZRB SiC复相陶瓷 纳米颗粒 多孔结构 

分 类 号：O631[理学—高分子化学] TQ343[理学—化学]