热等静压制备CF/Al复合材料的微观结构及性能

摘要

采用热等静压(HIP)工艺制备连续碳纤维(CF)增强Al基复合材料。利用扫描电镜、粒度仪和X射线衍射仪表征2A12铝合金粉末形貌、粒度分布和相组成；利用光学显微镜、扫描电镜和能谱仪观察复合材料的显微组织、断口形貌和界面扩散反应特征，并对其主要力学性能进行测试。结果表明：粉末形貌呈球形，粒度主要分布在150~180μm；复合材料致密，界面连接紧密无孔洞缺陷；与基体铝合金材料相比，复合材料的拉伸强度和断后伸长率分别提高5%和54%，断裂方式为脆性断裂；Al基体裂纹起源于粉末颗粒界面，CF/Al界面断口呈现CF拔出和断裂失效形式；CF/Al界面发生元素扩散，界面反应生成Al 4 C 3金属间化合物。%Aluminum matrix composite reinforced with continuous carbon fiber (CF) was manufactured by hot isostatic pressing (HIP). The morphology, grain size distribution and phase of the powders were investigated by scanning electron microscope (SEM), particle analyzer and X-ray diffraction (XRD). The microstructure, fracture surface morphologies and CF/Al interface reaction characteristic were observed by optical microscope (OM), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). The mechanical properties of the composites were also tested. The results indicate that, the powders are nearly spherical, the particle size is mainly 150−180μm;the composites are compact and the interface bonding is tight without porosity defect;compared with the aluminum matrix alloy, the tensile strength and elongation of the composites increase by above 5%and 54%, respectively, and the fracture mechanism is brittle fracture;the fracture of the Al matrix is along the powder interface, carbon fibers are pulled out and fractured in the CF/Al interface zone; the interface of the CF/Al appears element diffusion, and the interfacial reaction product is Al4C3 intermetallic compound.