聚锆碳烷/聚碳硅烷杂化先驱体转化制备ZrC-SiC复相陶瓷  

Preparation of ZrC-SiC multiphase ceramics by pyrolysis of polyzrocarbonane/polycarbosilane hybrid precursor

作　　者：赵哲 高强[1] 韩成 王应德[1] ZHAO Zhe;GAO Qiang;HAN Cheng;WANG Yingde(Science and Technology on Advanced Ceramic Fibers and Composites Laboratory,College of Aerospace Sciemce and Engineering,National University of Defense Technology,Changsha 410073,China)

机构地区：[1]国防科技大学空天科学学院新型陶瓷纤维及其复合材料重点实验室,长沙410073

出　　处：《材料工程》2023年第8期102-109,共8页Journal of Materials Engineering

基　　金：国家自然科学基金项目(52202031)。

摘　　要：采用聚锆碳烷PZC和聚碳硅烷PCS作为杂化先驱体聚合物,通过脱氢耦合反应制备富含活性交联位点的ZrC-SiC复相陶瓷先驱体PZCS,研究先驱体陶瓷化机理及最终陶瓷的组成结构。结果表明:PZCS先驱体由于促进了陶瓷化过程中活性基团的交联,850℃下其陶瓷产率(71.84%,质量分数,下同)显著高于PZC(51.40%)或PCS(53.46%)先驱体。同时,在Zr-Cp的催化下,通过先驱体之间的协同作用近程碳与Zr,Si元素直接转化生成碳化物陶瓷,避免了碳热还原反应对陶瓷的损伤,并有效降低了烧结温度。PZCS先驱体经陶瓷化处理后生成兼具耐高温组元和抗氧化组元的ZrC-SiC纳米复相陶瓷,ZrC相和SiC相可以相互抑制结晶、细化晶粒,其中ZrC晶粒尺寸为25.4 nm,纳米复相结构的生成有利于提升超高温陶瓷的综合性能。The ZrC-SiC multiphase ceramic precursor of PZCS with abundant active cross-linking sites was prepared by a dehydrocoupling reaction between polyzrocarbonane(PZC)and polycarbosilane(PCS).The ceramization mechanism of PZCS and the composition and structure of the final ceramic were studied.The results reveal that the ceramic yield of PZCS(71.84%,mass fraction,the same below)is significantly higher than that of PZC(51.40%)or PCS(53.46%)precursor at 850℃,due to the promoted crosslinking of active groups during the ceramization process.Meanwhile,under the catalysis of Zr-Cp,the short-range carbon and Zr,Si elements are directly converted to carbide ceramics through the synergistic transformation of two polymers in PZCS,avoiding the adverse effects of carbon thermal reduction to the ceramics,and effectively reducing the sintering temperature.The ZrC-SiC nanocomposite ceramic with both high temperature resistance and oxidation resistance components is prepared after pyrolysis of PZCS.The generation of ZrC and SiC phases could inhibit crystallization and refine the grain size,of which the ZrC grain size is 25.4 nm.Moreover,the generation of ZrC-SiC nanocomposite structure would be beneficial for improving the comprehensive performance of ultra-high temperature ceramics.

关 键 词：聚锆碳烷 聚碳硅烷 协同转化 ZrC-SiC 复相陶瓷 

分 类 号：TQ174.75[化学工程—陶瓷工业]