文献类型：期刊文献

英文题名：Polymer-Derived SiC/B4C/C Nanocomposites: Structural Evolution and Crystallization Behavior

作者：Jiang, Yun[1];Li, Junfei[1];Huang, Farong[1];Zhou, Yan[1];Du, Lei[1]

机构：[1]E China Univ Sci & Technol, Inst Mat Sci & Engn, Minist Educ, Key Lab Specially Funct Polymer Mat & Related Tec, Shanghai 200237, Peoples R China

年份：2014

卷号：97

期号：1

起止页码：310

外文期刊名：JOURNAL OF THE AMERICAN CERAMIC SOCIETY

收录：;EI(收录号：20140717306183);WOS:【SCI-EXPANDED(收录号:WOS:000329198800038)】；

基金：This work was supported by the Shanghai Leading Academic Discipline Projects (B502).

语种：英文

外文关键词：Crystallization - Silicon carbide - Boron - Boron carbide - Amorphous silicon - Graphite - Ceramic materials - Nanocomposites - Graphitization

摘要：Structural evolution and crystallization behavior between 600 degrees C and 1450 degrees C during the preparation of bulk SiC/B4C/C nanocomposites by the pyrolysis of CB-PSA preceramic were investigated. The CB-PSA preceramic converts into carbon-rich Si-B-C ceramics up to 800 degrees C. Structural evolution and crystallization of Si-B-C materials could be controlled by adjusting the pyrolytic temperature. The Si-B-C ceramics are amorphous between 800 degrees C and 1000 degrees C. Phase separation and crystallization begin at 1100 degrees C. The crystallization of beta-SiC takes place at 1100 degrees C and B4C nanocrystallites generate at 1300 degrees C. The sizes of beta-SiC and B4C nanocrystals increase with the pyrolytic temperature rising. In addition, the boron-doping effect on structural evolution was studied by comparing the crystallization and graphitization behavior of Si-B-C ceramics and the corresponding Si-C materials. Boron is helpful for the growth of beta-SiC nanocrystals and the graphitization, but harmful for the nucleation of beta-SiC crystallites.