惰性气氛下低氧碳化硅纤维结构和性能的演变  

Evolvement of Structures and Properties of Silicon Carbide Fibers with Low Oxygen Content under Inert Gas Atmosphere

作　　者：李亮[1] 简科[1] 王亦菲[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：《有机硅材料》2017年第1期15-18,共4页Silicone Material

基　　金：国防科学技术大学创新群体资助(CJ12-XX-01)

摘　　要：将低氧碳化硅纤维(KD-Ⅱ)在氩气中分别于1 400、1 600、1 800和2 000℃热处理1 h,对纤维强度和微观结构进行了测试和表征。结果表明,随着热处理温度的升高,KD-Ⅱ中β-SiC晶粒不断长大,孔隙逐渐增多,强度下降。经1 800℃热处理后纤维拉伸强度保持在1 GPa以上。纤维拉伸强度的下降主要是因为β-SiC晶粒的长大、SiC_xO_y相的分解和自由碳的增多。A precursor - derived SiC fiber with low oxygen content （ KD - Ⅱ） was treated respectively at 1400℃, 1600℃, 1800℃ and 2000℃ for 1 hour in flow argon. The residual strength and microstructures were characterized by XRD and SEM analysis. Results showed that with the temperature increased, the crystal size and porosity of β - SiC in fibers increased while the tensile strength decreased. The strength of fiber could remain over 1 GPa after heat treatment at 1800℃. The strength decrease of the fiber was caused by the growth of β -SiC crystal, decomposition of SiCxOy phase and the increase of the free carbon.

关 键 词：低氧含量 碳化硅纤维 强度 惰性气氛 孔隙 晶粒 

分 类 号：TQ343.6[化学工程—化纤工业]