化学气相渗透法制备炭/炭复合材料的显微结构和力学性能研究  

Study on Microstructure and Mechanical Properties of Carbon /Carbon Composite Obtained by Chemical Vapor Infiltration

作　　者：黄群[1] 陈腾飞[1] 刘磊[1] 马艺林[1] 何平鸽 

机构地区：[1]中南大学粉末冶金国家重点实验室,湖南长沙410083

出　　处：《矿冶工程》2014年第4期111-114,共4页Mining and Metallurgical Engineering

基　　金：国家高技术研究发展计划(863计划)资助项目(2012AA03A207)

摘　　要：以天然气为碳源,氢气为载气,采用等温化学气相渗透工艺对预制体初始密度为0.5 g/cm3(纤维体积分数为28%)的针刺整体毡进行致密化,在70 h内制备出表观密度为1.76 g/cm3的炭/炭复合材料。采用压汞法对复合材料的开孔孔径分布进行了分析,用偏光显微镜和扫描电镜观察了基体的微观组织,分析了三点抗弯试样的断口形貌。结果表明,复合材料中的开孔以小于40μm的微孔为主,基体热解炭几乎全部由粗糙层热解炭组成,仅在化学气相渗透的初始阶段在炭纤维的表面形成了很薄的一层各向同性热解炭,复合材料的抗弯强度达到210 MPa。With natural gas as carbon source and hydrogen as carrier, carbon/carbon composite （ with an apparent density of 1.76 g/cm3 ） was prepared within 70 hours by densifying the preform of needle-punched integrated carbon felt with an initial density of 0.5 g/cm3（ volume fraction of 28%） by chemical vapor infiltration. The size distribution of open pores of the C/C composite sample was measured by mercury intrusion method. The microstructure of the composite was investigated by polarized light microscope （ PLM） and scanning electron microscope. And the mechanical properties were tested by three point bending method. Results show that the size of most of open pores was less than 40 μm, and the matrix of pyrocarbon mostly consisted of rough laminar pyrocarbon, except for one layer of isotropic pyrocarbon around the carbon fiber, which was formed at the beginning of infiltration process. The flexural strength of the C/C composite was about 210 MPa.

关 键 词：炭 炭复合材料 化学气相渗透 显微结构 孔径分布 力学性能 

分 类 号：TB332[一般工业技术—材料科学与工程]