摘要
在氧化性气氛(21%O2+79%Ar)、不同拉应力下研究SiC涂层C/C复合材料在1 000℃和1 300℃的氧化失效行为;采用扫描电镜观察SiC涂层C/C复合材料氧化失效后的断口形貌。试验结果表明:当温度为1 000℃,拉应力由C/C复合材料拉伸强度的20%增加至50%时,SiC涂层C/C复合材料的应力氧化明显加剧,寿命由大于5.00 h缩短到2.92 h,应力对SiC涂层C/C复合材料的寿命有显著影响;当拉应力为C/C复合材料拉伸强度的50%,温度为1 000℃和1 300℃时,材料均在低温区断裂,应力氧化寿命分别为2.92 h和2.62 h,温度对应力氧化寿命的影响不明显;应力氧化失效以纤维的氧化失效为主,外加拉应力起促进作用。
Oxidation failure behavior of C/C composites with SiC coating in oxygen environment （21% O2＋79% Ar） under different tensile stresses at 1 000℃ and 1 300℃ were conducted. Microstructures of fracture surfaces of C/C composites with SiC coating were observed by SEM after stress oxidation. The experimental results show that when tensile stress increases from 20%σ （σ is ultimate tensile strength） to 50%σ at 1 000℃, the oxidation of the C/C composites with SiC coating accelerates obviously and the lives decrease from more than 5.00 h to 2.92 h, which indicates that the stresses greatly impacts the lives. Under 50% σ at 1 000 ℃ and 1 300 ℃, C/C composites are fractured in the low temperature zone and their lives are 2.92 h and 2.62 h, respectively, which indicates that the temperatures have no obvious effects on the lives. The failure of the C/C composites is mainly due to the oxidation of carbon fibers and tensile stress accelerates the failure.
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2008年第5期951-955,共5页
Journal of Central South University:Science and Technology
基金
国家“973”计划资助项目(2006CB600908)
