5052与6061异种铝合金搅拌摩擦焊接头的组织和力学性能

Microstructure and mechanical properties of 5052-6061 dissimilar Al alloy welded joint by friction stir welding

采用搅拌摩擦焊(FSW)方法对6 mm厚的5052和6061异种铝合金进行了焊接,采用光学显微镜(OM)、扫描电镜(SEM)分析母材和焊接接头的显微组织和断口形貌,利用XRD分析了搅拌区域的物相组成,并测试了室温拉伸性能和显微硬度。结果表明,5052合金置于前进侧时更有利于材料在焊核区域的相互混合,焊接接头的最低硬度在5052合金一侧热影响区(HAZ),并在这个区域发生了断裂,断裂特征为韧性断裂。焊接接头的最大抗拉强度为225 MPa,伸长率为5.77%。

The 5052 and 6061 dissimilar aluminum alloy with the thickness of 6 mm were welded by friction stir welding ( FSW ) . Microstructure and fractographs of the friction stir welding joint and base metal were researched by means of optical microscope( OM) and scanning electron microscope ( SEM ) , respectively. Stir zone phase was analysed by XRD, meanwhile, the tensile properties and microhardness at room temperature were measured.The results show that the base materials are more effective to mix in the weld nugget when 5052 alloy is placed on the advancing side.The minimum hardness of the weld joint occurrs on the heat affects zone ( HAZ) of 5052 alloy side, where the failure occurrs which can be defined as ductile fracture.The maximum tensile strength and elongation of the weld joint are 225 MPa and 5.77%, respectively.