原位气相生长法制备碳纳米管/Al2O3陶瓷复合材料

以Al₂O₃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/Al₂O₃陶瓷复合材料。结果表明，Al₂O₃陶瓷体中均匀分布有可观量的多壁CNTs，碳管根部嵌于Al₂O₃晶粒间并从晶粒表面生长出。在Al₂O₃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/Al₂O₃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3.7 S/m，较纯Al₂O₃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。

Fabrication of carbon nanotubes/Al2O3 ceramic composites by in-situ chemical vapor deposition growth method

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.