碳源组成对化学气相渗透C/C复合材料致密化及热解炭结构的影响  

Effects of carbon source composition on densification of C/C composites and microstructure of pyrolytic carbon derived from chemical vapor infiltration

作　　者：房冲[1] 王雅雷[1] 熊翔[1] 汤中华[1] 陈招科[1] 孙威[1] FANG Chong WANG Yalei XIONG Xiang TANG Zhonghua CHEN Zhaoke SUN Wei(State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China)

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《复合材料学报》2016年第11期2609-2617,共9页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(51202295);中国博士后科学基金(2014M562129);一院高校联合创新基金(CALT201507)

摘　　要：为分析碳源在化学气相渗透过程中的沉积机制,以碳纤维针刺整体毡为预制体,添加丙烯(C_3H_6)的天然气混合气体为碳源,研究了碳源组成对C/C复合材料致密化及热解炭结构的影响。结果表明:相比于以天然气为碳源,以添加了适当比例C_3H_6的天然气为碳源,可有效提高C/C复合材料的致密化速率及密度分布均匀性;同时,有利于生成高织构的热解炭。最优条件(9vol%C_3H_6)下沉积100h后,C/C复合材料的密度和径向密度偏差分别为1.40g/cm^3和0.04g/cm^3,热解炭为均一的粗糙层结构,石墨化度高;而以天然气作碳源时,密度和径向密度偏差分别为1.17g/cm^3和0.07g/cm^3,热解炭为二元带状结构,石墨化度较低;当C_3H_6比例增加到17vol%时,其密度和径向密度偏差分别为1.28g/cm^3和0.10g/cm^3,密度及密度分布均匀性较最优条件下制备的复合材料明显降低。In order to analyze the deposition mechanism of carbon source during the chemical vapor infiltration process,using carbon fiber neddled flet as preform,propylene（C_3H_6）added natural gas mixture gas as carbon source,the effects of carbon source composition on densification of C/C composites and microstructure of pyrolytic carbon were investigated.The results show that compared with using natural gas as carbon source,using a moderate ratio of C_3H_6 added natural gas as carbon source can improve the densification efficiency and density distribution uniformity of C/C composites effectively.At the same time,it is beneficial to form high texture pyrolytic carbon.After deposition for 100 hunder the optimal condition（9vol% C_3H_6）,the density and density deviation at radial direction of C/C composites are 1.40g/cm^3 and 0.04g/cm^3 respectively,the pyrolytic carbon is homogeneous rough laminar structure,and the graphitization degree is high.While when using natural gas as carbon source,the density and density deviation at radial direction are 1.17g/cm^3 and 0.07g/cm^3 respectively,the pyrolytic carbon is binary banded structure,and the graphitization degree is lower.When the ratio of C_3H_6 is improved to 17vol%,the density and density deviation at radial direction of it are 1.28g/cm^3 and 0.10g/cm^3 respectively.Compared to the composite prepared under the optimal condition,the density and density distribution uniformity decrease obviously.

关 键 词：混合碳源 C/C复合材料 化学气相渗透 密度分布均匀性 显微结构 

分 类 号：TB332[一般工业技术—材料科学与工程]