摘要
考察了Nicalon NL202SiC纤维经热空气环境脱胶之后,在惰性气氛下进行高温热处理前后,包括热失重、元素组成、物相组织、表面形貌、力学性能及电阻率等结构与性能所发生的变化。研究表明,热处理温度为1 200℃时,主要是因高电阻率的连续相无定型态SiCxOy的分解,纤维电阻率大幅降低,介电损耗能力提升,有望用于吸波材料。而热处理温度超过1 200℃时,剧烈的热分解,导致纤维结构的缺陷;且快速的晶化,导致纤维拉伸断裂模式由非晶态脆性断裂转变为多晶态沿晶断裂。所有这些,都导致纤维强度的显著下降。
The commercial Nicalon 202 SiC fiber was exposed in thermal air to degum and heat treated in argon gas from 1 100 to 1 400℃.Change of the chemical,structural and electrical properties of the resultant fibers as a function of thermal treatment temperature were studied.The results showed that the SiCxOy phase decomposed evidently above 1 200℃,which led to the formation and crystallization of SiC.With the raise of the heating temperature,the tensile strength of fiber decreased,the specific conductivity and dielectric loss of the fiber increased.Moreover,after heating at 1 400 ℃ the fracture behavior of the fiber turned to intergranular mode from amorphous brittleness mode.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2015年第14期14023-14026,共4页
Journal of Functional Materials
基金
国家自然科学基金面上资助项目(51072169)
国家自然科学基金青年基金资助项目(51302234)
深圳市科创委知识创新计划资助项目(JCYJ20130329150151152)
关键词
SIC纤维
微观形貌
物相组成
电阻率
Nicalon NL-202 SiC fibers
microstructure
specific resistivity
dielectric properties
