(南昌大学 机电工程学院，南昌 330031)
摘 要: 将Al粉、Zn粉、碳纳米管(CNTs)混合料按照质量比为3׃1׃X(X=0，0.5，1.0，1.5)压块，并用钟罩压入法将这些预先制备的压块加入到合金熔体中制备AZ31/CNTs复合材料。测试该复合材料的力学性能，利用扫描电子显微镜(SEM)、能谱分析仪(EDS)、X射线衍射仪和光学显微镜对AZ31/CNTs复合材料的金相试样、断口形貌进行表征和分析。结果表明：钟罩压块法可以有效地将碳纳米管分散到镁合金熔体中；CNTs对AZ31镁合金的力学性能有较强的增强效果，与本研究中的铸造AZ31合金相比，AZ31/CNTs复合材料的最大抗拉强度和伸长率分别提高41.3%和119.4%，弹性模量和显微硬度分别提高67.8%和66.9%；CNTs对AZ31镁合金基体晶粒的细化作用显著，与镁基体界面结合较好；复合材料试样断口形貌由韧窝和撕裂棱组成，呈现准解理断裂特征。
关键字: AZ31镁合金；碳纳米管；预制块；复合材料；力学性能
prepared by adding CNTs block with plunger
（School of Mechatronics Engineering, Nanchang University, Nanchang 330031, China）
Abstract:Precast blocks were prepared with powders of Al, Zn and carbon nanotubes with mass ratio of 3׃1׃X(X=0, 0.5, 1.0, 1.5), and then the carbon nanotubes AZ31 composites were produced by immersing the precast block into the alloy melt by adding CNTs block with plunger. The mechanical properties of the as-cast AZ31 alloy based composites (AZ31/CNTs) were tested and their microstructures and fracture morphology were observed by metalloscopy, scanning electron microscopy (SEM), energy depressive spectroscopy (EDS) and X-ray diffractometry. The results show that the CNTs are dispersed effectively by bell jar immersing precast block casting. The maximal tensile strength and the elongation of the AZ31/CNTs composites are enhanced by 41.3% and 119.4%, respectively, and the elastic modulus and micro-hardness are also raised by 67.8% and 66.9%, respectively, when compared with those of the as-cast AZ31 Mg alloys. The CNTs can greatly refine the grains of the composites, playing a good role in reinforcing the matrixes of AZ31 Mg alloy. The fracture sections of the composites mainly consist of dimples and prisms, which demonstrates quasi- cleavage fracture modes.
Key words: AZ31 Mg alloy; carbon nanotubes; precast block; composite; mechanical properties
