Dong Jialiang, Zhang Datong, Zhang Weiwen, Zhang Wen, Qiu Cheng
National Engineering Research Center of Near-net shape Forming for Metallic Materials, South China University of Technology, Guangzhou 510640, China.
Materials (Basel). 2018 Feb 27;11(3):342. doi: 10.3390/ma11030342.
In this work, the dissimilar joint of AA7003-T4 and 6060-T4 alloy has been produced by friction stir welding (FSW). The microstructure was examined by optical microscope (OM), electron back scattered diffraction (EBSD), transmission electron microscopy (TEM), and the mechanical properties of the joint were investigated. It is demonstrated that sound dissimilar joint can be produced through FSW. In the nugget; precipitations dissolve into the matrix and η' reprecipitate subsequently; and the elongated aluminum grains are replaced by fine and equiaxed grains due to dynamic recrystallization (DRX). In the heat affected zone (HAZ), coarse β' and η precipitates are formed and the aluminum grains are coarser as compared to the base materials. In the thermo-mechanical affected zone (TMAZ), equiaxed and elongated grains coexist due to incomplete DRX. The ultimate tensile strength of the dissimilar joint is 159.2 MPa and its elongation is 10.4%. The weak area exists in the HAZ of 6060 alloy, which is placed in the retreating side during FSW. The correlations between the microstucture and mechanical properties of the dissimilar joint are discussed.
在本研究中，通过搅拌摩擦焊（FSW）制备了AA7003-T4和6060-T4合金的异种接头。采用光学显微镜（OM）、电子背散射衍射（EBSD）、透射电子显微镜（TEM）对微观结构进行了观察，并对接头的力学性能进行了研究。结果表明，通过搅拌摩擦焊可以制备出质量良好的异种接头。在焊核区，析出相溶解于基体中，随后η'相重新析出；由于动态再结晶（DRX），拉长的铝晶粒被细小等轴晶粒所取代。在热影响区（HAZ），形成了粗大的β'和η析出相，与母材相比，铝晶粒更粗大。在热机械影响区（TMAZ），由于不完全动态再结晶，等轴晶粒和拉长晶粒共存。异种接头的抗拉强度为159.2MPa，伸长率为10.4%。6060合金热影响区存在薄弱区域，该区域位于搅拌摩擦焊过程中的后退侧。讨论了异种接头微观结构与力学性能之间的关系。
