原位气相生长法制备碳纳米管/Al_2O_3陶瓷复合材料

Fabrication of carbon nanotubes/Al_2O_3 ceramic composites by in-situ chemical vapor deposition growth method

以Al_2O_3陶瓷成型体为基体,通过化学气相反应在陶瓷体内原位生长碳纳米管(CNTs),制备出CNTs/Al_2O_3陶瓷复合材料。结果表明,Al_2O_3陶瓷体中均匀分布有可观量的多壁CNTs,碳管根部嵌于Al_2O_3晶粒间并从晶粒表面生长出。在Al_2O_3陶瓷成型体中原位生长CNTs需严格控制生长条件,尤其是生长温度(850℃),温度过高和过低都难以长出CNTs,此外造孔剂、碳源和催化剂也影响CNTs的原位生长。对原位生长的CNTs/Al_2O_3复合体进一步高温烧结获得致密化的复合材料,其导电率达3.7S/m,较纯Al_2O_3提高13个数量级。在陶瓷成型体中原位生长CNTs是一步法制备CNTs/陶瓷复合材料的新方法,可用于发展高性能的结构陶瓷和具有导电导热等多功能特性的新型陶瓷复合材料。

Carbon nanotubes（CNTs）/Al2O3 composite was fabricated by in-situ chemical vapor deposition growth of CNTs in Al2O3 ceramic green body during its sinetering.The results show that multi-walled CNTs have been sucessfully grown and distributed homogeneously in the Al2O3 ceramic matrix.The roots of CNTs embed in the Al2O3 grains reveal directly growth and firmly combination.The in-situ growth of CNTs in the Al2O3 ceramic matrixes requires strictly controlling of the preparation conditions.The CNTs grow at 850℃,while no CNTs are observed in the samples fabricated at higher or lower temperatures.The adding of the pore former,carbon source and catalyst all affect the in-situ growth of CNTs.The entire CNTs/Al2O3 composite with densified structure was obtained through subsequent sintering at higher temperature.The CNTs offers the CNTs/Al2O3 obviously electrical conductivity up to 3.7 S/m,13 orders of magnitude higher than that of the bare Al2O3.This in-situ growth in preformed ceramic body as one-step strategy is attractive for the development of CNTs/ceramic composites combined with high mechanical and multi-functional properties.