真空气氛下非晶硅碳氮(SiCN)陶瓷的高温晶化行为  

Crystallization of Amorphous SiCN Ceramic Annealed in Vacuum

作　　者：夏熠[1] 乔生儒[1] 王强强[1] 张程煜[1] 韩栋[1] 李玫[1] 

机构地区：[1]西北工业大学超高温结构复合材料实验室,西安710072

出　　处：《无机材料学报》2009年第4期827-830,共4页Journal of Inorganic Materials

基　　金：国家自然科学基金(50772089);高等学校学科创新引智计划(B08040)

摘　　要：以六甲基二硅氮烷为单一前驱体,采用电热裂解化学气相沉积技术制备了SiCN陶瓷.借助X射线衍射仪、透射电子显微镜研究了真空环境中非晶SiCN陶瓷在1300～1900℃范围内的晶化行为,并根据研究结果,运用分解-结晶机理解释了其晶化过程.非晶SiCN陶瓷在低于1300℃开始发生分解,形成富Si-C区域,并最终发生β-SiC结晶.其结晶度随热处理温度的升高而愈加明显.在1700℃处理时发生β-SiC→α-SiC相变.分解形成的N-难以与Si-结合形成富Si-N区域,最终以N2形式溢出,在整个热处理温度范围没有出现氮气下热处理时存在的Si3N4结晶.SiCN ceramic was fabricated by electro-thermal pyrolysis using hexamethyldisilazane as precursor.X-ray diffraction and transmission electron microscope were employed to study crystallization process of amorphous SiCN after annealing at temperature from 1700℃ to 1900℃ in vacuum.Decomposition-crystallization mechanism was used to characterize its crystallization process.Amorphous SiCN begin to decompose below 1300℃ in vacuum and Si-C-enriched districts are formed and then changes to form β-SiC crystal.Crystallinity degree increases as treated temperature rises.Phase transition from β-SiC to α-SiC occurs after annealing at 1700℃.The nitrogen is released in the form of N2 and Si3N4 crystal is not detected though it often exists in the SiCN annealed in N2 atmosphere.

关 键 词：非晶SiCN陶瓷 晶化行为 相变 显微结构 

分 类 号：TB332[一般工业技术—材料科学与工程]