(哈尔滨工业大学 材料科学与工程学院， 哈尔滨 150001)
摘 要: 利用金相显微镜、 扫描电镜、 透射电镜和万能拉伸试验机等手段考察了粒度为0.3μm的Al2O3颗粒(体积分数为26%)增强6061Al复合材料在热挤压前后的显微组织及室温拉伸性能。 结果表明： 以10∶1的挤压比热挤压后复合材料组织的均匀性得到了明显改善， 显微组织变化上呈现位错由压铸态的近无位错转变为位错有明显增殖特征，并促进了时效析出； 复合材料挤压材的抗拉强度、 屈服强度和延伸率较压铸材普遍提高； 热挤压没有改变复合材料的断裂机制， 由于挤压后颗粒分布均匀等原因， 使复合材料的塑性得到改善。
关键字: 热挤压变形； Al2O3p/Al； 金属基复合材料； 显微组织；力学性能
sub-micro Al2O3p/Al composite
（School of Materials Science and Engineering，
Harbin Institute of Technology， Harbin 150001， China）
Abstract:The microstructure and mechanical properties of Al2O3p/6061Al composite reinforced by Al2O3 particle with size of 0.3μm(volume fraction 26%) before and after hot extrusion were investigated by OM， SEM， TEM and tensile test. The results show that, the microstructure of the composite after hot extrusion with the extrusion ratio of 10∶1 becomes more uniformly， and compared with the microstructure characteristic of nearly free dislocation before hot extrusion， more dislocations are found in the microstructure. The ultimate strength， yield strength and elongation of the composite are also increased after hot extrusion. The hot extrusion do not change the fracture mechanism of the composite and the plasticity is improved due to the evenly distributed particles after hot extrusion.
Key words: hot extrusion deformation； Al2O3p/Al； metal matrix composite； microstructure； mechanical properties
