高等学校化学学报
高等學校化學學報
고등학교화학학보
CHEMICAL JOURNAL OF CHINESE UNIVERSITIES
2014年
9期
2050-2054
,共5页
葛凯凯%邱文丰%韩伟健%叶丽%赵爱军%赵彤
葛凱凱%邱文豐%韓偉健%葉麗%趙愛軍%趙彤
갈개개%구문봉%한위건%협려%조애군%조동
液相前驱体%裂解%碳热还原%ZrB2/SiC复相陶瓷%纳米颗粒%多孔结构
液相前驅體%裂解%碳熱還原%ZrB2/SiC複相陶瓷%納米顆粒%多孔結構
액상전구체%렬해%탄열환원%ZrB2/SiC복상도자%납미과립%다공결구
Liquid precursor%Pyrolysis%Carbothermal reduction%ZrB2/SiC multiphase ceramic%Nano particles%Porous structure
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.
以聚鋯氧烷為鋯源,聚硼硅氮烷兼作硼源、硅源和碳源,通過共混得到ZrB2/SiC液相前驅體,該前驅體經高溫裂解得到ZrB2/SiC複相陶瓷.對ZrB2/SiC前驅體的裂解行為、陶瓷產物結構及微觀形貌進行瞭錶徵.結果錶明, ZrB2/SiC前驅體經1400℃裂解後保持無定形狀態,1500℃處理後析齣t-ZrO2晶體,1600℃時體繫髮生碳熱還原反應生成ZrC,同時析齣SiC晶體,1700℃時生成ZrB2,最終陶瓷產物晶相組成為ZrB2/SiC.在1500~2000℃範圍內,隨著處理溫度的升高,陶瓷由緻密結構變為多孔結構,最終陶瓷產物由呎吋為100~300 nm的納米顆粒堆積而成,各元素分佈均勻.
이취고양완위고원,취붕규담완겸작붕원、규원화탄원,통과공혼득도ZrB2/SiC액상전구체,해전구체경고온렬해득도ZrB2/SiC복상도자.대ZrB2/SiC전구체적렬해행위、도자산물결구급미관형모진행료표정.결과표명, ZrB2/SiC전구체경1400℃렬해후보지무정형상태,1500℃처리후석출t-ZrO2정체,1600℃시체계발생탄열환원반응생성ZrC,동시석출SiC정체,1700℃시생성ZrB2,최종도자산물정상조성위ZrB2/SiC.재1500~2000℃범위내,수착처리온도적승고,도자유치밀결구변위다공결구,최종도자산물유척촌위100~300 nm적납미과립퇴적이성,각원소분포균균.
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.