碳纳米管增强铝基复合材料制备及性能研究

Preparation of CNTs Reinforced Al-matrix Composite and Study of Their Mechanical Properties

采用真空热压烧结法制备碳纳米管与Si O2多相增强铝基复合材料,测量复合材料的体积密度,根据其理论密度计算其致密度;再对制得的复合材料进行硬度、抗压强度、抗剪强度等力学性能测试,并观察样品的剪切断口微观形貌,研究CNTs对复合材料力学性能的影响。低含量的碳纳米管由于其在铝基体中的分散性及弥散度较好,作为第二相增强相,所制备的铝基复合材料的致密度、硬度、抗压强度与剪切强度均优于高含量碳纳米管增强铝基复合材料。CNTs的含量、以及其在铝基体中的弥散度是影响铝基复合材料力学性能的关键因素。

Carbon nanotubes （CNTs） reinforced Al-matrix composite is attracted much attention in the fields of aeronautics and astronautics, structural materials, and electronic packaging materials, since they combine both the advantages of Al casting alloys, including as light weight, good mechanical property and high abrasion resistance, and those of carbon nanotubes, including as extremely high mechanical strength, as well as high thermal conductivity.In this study, multi-phased Al-matrix composite, reinforced with CNTs and SiO2 is prepared by using a vacuum hot-pressing sintering method.The density of the composite is calculated according to measured bulk density and the theoretical density is calculated as well; mechanical properties are determined by microVickers hardness, compressive strength tests and tensile strength tests; the micro-morphology is observed by scanning electron microscope （ SEM）.The research results show that the density, hardness, compressive strength, and shear strength of lower MWCNTs content reinforced Al-matrix composite is better than that of higher CNTs content, which can attribute to better dispersity of CNTs as a secondary reinforce-phase in Al matrix.The content of CNTs, and the dispersity in Al matrix are significant factors which affect the mechanical property of Al-matrix composite.