搅拌摩擦加工对3003铝合金铸轧带组织和力学性能的影响

The influence on microstructure and mechanical properties of friction stir processed roll-casting strip of 3003 aluminum alloy

采用搅拌摩擦加工方法对3003铝合金铸轧带材进行加工,借助光学显微镜(OM)、扫描电镜(SEM)、电子背散射衍射技术(EBSD)、拉伸试验机、显微硬度仪和取向成像分析软件(OIM),分别对加工区及母材的显微组织与力学性能进行了研究.结果表明:该合金经搅拌摩擦加工后,搅拌区晶粒发生动态再结晶并且等轴细化,平均晶粒尺寸由母材的35.58μm减小至3.05μm;相比于母材,搅拌摩擦加工后带材的抗拉强度、平均硬度、延伸率均有所降低,分别为117.68MPa,37.82MPa,12.53%;加工区硬度沿横向呈"W"型不均匀分布,并且从加工区底部到上部依次升高.

The roll-casting strip of 3003 aluminum alloy was machined by friction stir processing.The mechanical properties of both processing zone and base metal were investigated by optical microscopy,scanning electron microscopy,electron backscatter diffraction（EBSD）,electronic universal test machine,microhardness tester and orientation imaging microscopy（OIM）.The results showed that there was a dynamic recrystallization and fine isometric crystal structure in the stir zone.The average grain size of base metal was reduced from 35.58μm to 3.05μm in the nugget zone.Comparing to base metal,the tensile strength and hardness and elongation of processed zone were decreased,and the value is 117.68MPa,37.82MPa,12.53%,respectively.Additionally,the micro-hardness was distributed asymmetrical as＂W＂along the vertical direction of processing zone,and the value increased from the bottom to the top.