SiC_xO_y相分解方式对SiCO(Al)纤维烧结致密化的影响  

Effect of SiC_xO_y Decomposition on Densification of SiCO(Al) Fibers during Sintering Process

作　　者：袁钦[1] 宋永才[1] 

机构地区：[1]国防科学技术大学新型陶瓷纤维及其复合材料重点实验室,长沙410073

出　　处：《无机材料学报》2016年第12期1320-1326,共7页Journal of Inorganic Materials

基　　金：湖南省高校科技创新团队支持计划;国防科技大学创新群体资助(CJ 12-01-01)~~

摘　　要：研究了SiCO（Al）纤维向SiC（A1）纤维的高温转化过程，并研究了纤维中SiCxOy相的分解特征及不同高温处理方式对纤维结构和烧结致密化的影响。结果表明：纤维中SiCxOy相分解的温度范围为1430-1850℃，当采用连续处理方式处理，即使在1800℃下，纤维芯部SiCxOy相未能彻底分解，且快速分解速率导致纤维中形成粗大结晶颗粒和气孔，无法得到致密的高结晶结构。而在静态条件下处理，可以提高SiCxOy相分解程度。1650℃下保温处理1h后可以完全脱除SiCxOy相，同时保持晶粒均匀。再经过1900℃烧结，即可制得呈致密高结晶结构SiC（Al）纤维。The transformation from SiCO（Al） fiber to SiC（Al） fiber by high temperature heat-treatment was studied. The characteristics of SiCxOy decomposition and effects of different heating approaches on microstructure and densification processing of SiCO（Al） fibers were investigated. It was found that SiCxOy phase typically decomposed at temperature ranged from 1430℃ to 1850℃. The SiCxOy phase in the core area of fiber could not be eliminated completely by continuous heat-treatment, even at the temperature as high as 1800℃. Furthermore, large pore faults and grain coarsening tended to generate in the fibers due to over-high decomposition rate, which led to loose structure of fibers. By contrast, static heat-treatment could increase the degree of SiCxOy decomposition. The SiCxOy phase could be completely removed when the fibers were heat-treated at 1650℃ for 1 h, and big pores and heterogenous grains were suppressed. Finally, densified SiC（Al） fibers with large β-SIC grains could be achieved after sintering at 1900℃.

关 键 词：SiCO(Al)纤维 SiC(Al)纤维 SiCxOy相 Β-SIC 致密化 

分 类 号：TQ343[化学工程—化纤工业]