高性能碳纳米管增强AZ91D镁基复合材料的制备

摘要

采用球磨加搅拌铸造工艺制备了CNTs(质量分数为0.1％)增强的AZ91D镁基复合材料.通过光学显微镜、X射线衍射仪、傅里叶红外光谱仪、扫描电子显微镜、透射电子显微镜和室温拉伸试验对复合材料进行表征和分析.结果表明:碳纳米管在镁基体中分散很均匀,并且复合在基体中的碳纳米管结构较完整.与AZ91D基体相比,复合材料屈服强度和伸长率分别提高了47.2％和112.2％.碳纳米管在基体中的均匀分散且与基体形成的强界面结合使复合材料屈服强度和伸长率同时得到了提升.此外,晶粒细化和基体中均匀分散的β相(Mg17Al12)也有助于复合材料力学性能的提高.%AZ91D alloy composites with 1.0％ CNTs have been fabricated by a method combined ball milling with stirring casting.The composite was investigated using optical microscopy(OM),X-ray diffraction(XRD),Fourier transform infrared spectroscope (FT-IR),scanning electron microscope (SEM),transmission electron microscope (TEM) and room temperature (RT) tensile test.The results show that CNTs were homogeneously distributed in the matrix and maintained integrated structure.The yield strength and ductility of AZ91D/CNTs composite were improved by 47.2％ and 112.2％,respectively,when compared with the AZ91 alloy.The uniform distribution of CNTs and the strong interfacial bonds between CNT and the matrix are dominated to the simultaneous improvement of yield strength and ductility of the composite.In addition,the grain refinement as well as the finerβ phase (Mg17Al12) with homogenous distribution in the matrix can also slightly assist to the enhancement of the mechanical properties of the composite.