摘要
以不同比例甲烷氢气(CH4、CH4/H2=3/1、CH4/H2=2/1)作为前驱体,采用等温等压化学气相渗积工艺,在1100℃,气压为5kPa下,经过500h制备相应的炭/炭复合材料样品。研究了密度随致密化时间的变化规律和样品的密度分布,采用偏光显微镜、高温热处理后X射线衍射、三点弯曲实验对材料进行了表征,结果表明:甲烷体系中氢气的加入在致密化初期会对沉积速率有明显的减小作用,最终得到的样品密度分布均匀。同时CH4/H2=2/1前驱体获得近乎单一的粗糙层结构,具有最高的石墨化度,氢气的加入提高了材料密度,提高了炭/炭复合材料的力学性能。
The C/C composites prepared by isothermal chemical vapor infiltration were focused, used methane/hy- drogen in different ratio（CH4, CH4/H2 = 3/1, CH4/H2 = 2/1） as the precursor, under the temperature of 1100~C, pressure 5 kPa and through 500h. The influence of different methane/hydrogen ratio on the densification rate, microstructures and flexural strength of C/C composites was investigated. The properties of the samples were determined by three-point blend- ing tests, polarized light microscopy and X-ray diffraction. The result showed that the densification rate of C/C composites using methane as precursors was higher than that using methane/hydrogen precursor before 200h infiltration. The density of C/C composites tended to distribute uniformly after the addition of hydrogen, and the texture belonged to rough laminar when the ratio of methane/hydrogen was 2/1. These composites with the addition of hydrogen had higher graphitization de- gree and bulk density, and also the mechanical properties of the C/C composites were improved.
出处
《化工新型材料》
CAS
CSCD
北大核心
2013年第7期29-32,共4页
New Chemical Materials
基金
国家自然科学基金(21071011)
关键词
炭
炭复合材料
化学气相渗积
致密化速率
组织结构
力学性能
C/C composite, chemical vapor infiltration, densification rate, microstructure, mechanical property
