炭纤维表面生长纳米碳管对CVI热解炭结构的影响

Effect of carbon nanotubes growth on carbon fibers on microstructure of pyrolytic carbon matrices of C/C composites

以单向长纤维预制体为骨架,CO为碳源,Ni为催化剂颗粒,在预制体炭纤维表面催化热解生长纳米碳管(CNT),采用CVI工艺增密,制得含CNT的C/C复合材料,研究纤维表面生长不同加载量的CNT对CVI过程所沉积热解炭微观结构的影响。研究结果表明:由于CNT具有特殊结构,纤维表面适当含量CNT能诱导CVI过程中热解炭的有序沉积,在近纤维层得到高织构度热解炭,改善炭纤维与热解炭的结合状态,拓宽制备粗糙层热解炭的CVI工艺条件范围;但当有过量CNT存在时,由于CNT之间的纠结,反而不利于发挥CNT对热解炭的催化诱导作用。

Carbon nanotubes（CNT） were prepared with carbon fibers of unidirectional carbon preform by vapor deposition method taking CO as carbon source,Ni as catalyst.And then CVI method was used to density the preforms to get the C/C composites with CNT.The effect of CNT on the microstructure of pyrolytic carbon was investigated.The results show that proper amount of CNT on the surface of carbon fibers can induce the orderly deposition of pyrocarbon around carbon fibers and ajust the interface bonding between fibers and pyrocarbon during CVI,which widens the suitable CVI process rang to get RL PyC.But excess amount of CNT does not reflect the induction effect on PyC because of the intertwinement between CNTs.