碳纤维上原位生长碳纳米管对C/C复合材料弯曲性能的影响

Influence of in-situ grown carbon nanotubes on carbon fiber on the flexural properties of C/C composites

以碳毡为基底原位生长了碳纳米管(CNTs),借助化学气相渗透制备了CNTs-C/C复合材料。研究了催化剂含量对碳纳米管生长的影响以及不同含量碳纳米管对C/C复合材料弯曲性能的影响。结果表明:催化剂对CNTs产量影响较大,且含量越多,生成的CNTs量越大;原位生长CNTs引入的催化剂会导致CNTs-C/C复合材料弯曲性能变差;CNTs的加入改变了热解碳的沉积行为,诱导了球状和锥状小尺寸热解碳的形成,减少了微裂纹的出现。适量CNTs能提高C/C复合材料的弯曲强度和模量,并改善材料的断裂行为。

The carbon nanotubes （CNTs） were in-situ grown on carbon fiber felts and the hybrid felts were densified by chemical vapor infiltration （CVI） to prepare CNTs-C/C composites.The effects of catalyst content on the growth of CNTs and the effects of CNT content on the flexural properties of CNTs-C/C composites were investigated. The results show that catalyst content has a great influence on the yield of CNTs. More CNTs were obtained with the catalyst content increasing. The catalysts used for CNT growing deteriorate the flexural properties of C/C composites. The CNTs changes the infiltration behaviors of pyrocarbons and induces the formation of abundant small-sized spherical or cone-shaped pyrocarbons, which inhibits the formation of annular cracks in pyrocarbon matrix. The CNTs with a suitable content can increase the flexural strength and modulus and improve the fracture behavior of C/C composites.