Formation of nanocrystalline graphite in polymer-derived SiCN by polymer infiltration and pyrolysis at a low temperature

作     者：Mingxing LI Laifei CHENG Fang YE Conglin ZHANG Jie ZHOU Mingxing LI;Laifei CHENG;Fang YE;Conglin ZHANG;Jie ZHOU

作者机构：Science and Technology on Thermostructural Composite Materials LaboratoryNorthwestern Poly technical UniversityXi'an 710072China 

出 版 物：《Journal of Advanced Ceramics》 (先进陶瓷（英文）)

年 卷 期：2021年第10卷第6期

页      面：1256-1272页

核心收录：

学科分类：08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.51632007,51872229,and 52072304) National Science and Technology Major Project(Grant No.2017-VI-0007-0077) 

主　　题：polymer-derived ceramics(PDCs) silicon carbonitride(SiCN) free carbon carbonization dielectric property 

摘      要：The microstructure of polymer-derived ceramics(PDCs)was closely related to *** study demonstrated that SiCN matrix prepared by polymer infiltration and pyrolysis(PIP)at 900℃ inside a Si_(3)N_(4) whisker(Si_(3)N_(4w))preform with submicro-sized pores differed from its powder-consolidated analogue in both the content and structure of free *** analysis showed that PIP process had a higher free carbon *** spectroscopy and transmission electron microscopy(TEM)observation discovered a higher graphitization degree of free carbon and the existence of nanocrystalline graphite in SiCN *** properties of Si_(3)N_(4w)/SiCN composites were greatly enhanced when volume fraction of SiCN matrix reached 24.5%due to dielectric percolation caused by highly-lossy free *** of hydrocarbon released during pyrolysis by gas-state carbonization in Si_(3)N_(4) whisker preform was supposed to account for the high yield and graphitization degree of free carbon in PIP process.