复合铸造法制备纳米碳管增强镁基复合材料的研究

Study on Carbon Nanotubes/Magnesiuum Matrix Composites by Stir-casting

采用复合铸造的方法制备了碳纳米管(CNTs)增强镁基复合材料;对其力学性能进行了测试,并对显微组织进行了观察和分析。用透射电镜(TEM)和能谱(EDS)方法对 CNTs涂覆层的界面结构和成分进行分析,探讨了 CNTs对镁基复合材料的增强机理及作用机制。试验结果表明:加入CNTs后,复合材料的抗拉强度比基体最高可提高 150%以上,延伸率最高可提高30%以上,平均弹性模量可增加近 80%,硬度可升高 6HB;采用化学镀镍方法可在CNTs表面获得均匀的涂覆层,改善CNTs与基体的润湿和结合状况,提高CNTs对镁基材料的增强效果。CNTs对镁基材料具有较好的增强效果,能明显细化晶粒组织,促使复合材料的位错密度增加,大幅度提高复合材料的抗拉强度、延伸率、硬度和平均弹性模量。但在本文试验条件下,CNTs的加入量不能太高,否则,因CNTs难以分散而使复合材料的性能大幅下降。

In order to discuss the action mechanism of composite, it was made to carbon nanotubes(CNTs)/Magnesium matrix composite by Stir-casting method. Its mechanical properties were tested and microstructure of the composites was analyzed and the interface structure and component of plating and un-plating nanotubes carbon were also analyzed by TEM and EDS. The experimental results show that the tensile strength of composite can be enhanced by 150%, and the elongation percentage can be increased by 30%, and the Yong's modulus and hardness are also improved. Moreover adopting the Nichel-plating treatment, it can be acquired to uniform and firm binding plating coat in the CNTs surface. And the plating treatment on the surface of CNTs can improve the wettability and binding situation with the matrix. It is concluded that the CNTs can refine the grain, increase the dislocation density, strengthen Mg-base composites perfectly. Under conditions of the experiment, the amount of CNTs can not be exceed 1.0 Vol%, otherwise properties of composite material will decline remarkably for difficulty in dispersion of CNTs.