Microstructure Distribution and Tensile Anisotropy of Dissimilar Friction Stir Welded AM60 and AZ31 Magnesium Alloys  

作　　者：Jun-Lei Zhang Han Liu Yu-Lu Xie Guang-Sheng Huang Xiang Chen Bin Jiang Ai-TaoTang Fu-Sheng Pan 

机构地区：[1]State Key Laboratory of Mechanical Transmission,College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China [2]National Engineering Research Center for Mg Alloys,Chongqing University,Chongqing 400044,China

出　　处：《Acta Metallurgica Sinica(English Letters)》2020年第11期1487-1504,共18页金属学报（英文版）

基　　金：financially supported by the National Key Research and Development Plan(No.2016YFB0301104);the National Natural Science Foundation of China(Nos.51671041,51531002,U1764253)。

摘　　要：The microstructure distribution,tensile anisotropy and fracture behaviors in the dissimilar friction stir welded joint of AM60/AZ31 alloys were investigated.Experimental results showed that a significant grain refinement and an orientation fluctuation occurred in the weld.The grain size of AZ31 side in joint was obviously smaller than that of AM60 side.There was a higher percentage of low angle grain boundaries(LAGBs)and a lower degree of recrystallization in AZ31 side compared with those in AM60 side,especially for the thermo-mechanically affected zone in AZ31 side.The discrepancies of grain size distribution,recrystallization behavior and LAGBs in joint depended on the different initial state of two metals and the inhomogeneous temperature distribution in joint.In addition,the(0001)basal plane in weld was roughly parallel to the surface of the pin,showing the symmetrically distributed texture characteristics.The joint showed an obvious tensile anisotropy due to the special texture distribution.The comprehensive tensile properties of joint along the three directions decreased in the order:welding direction,45°direction and transverse direction.The maximum ultimate tensile strength,yield strength and elongation of the joint were 242 MPa,116 MPa and 21.2%,respectively.The fluctuations of grain size and texture in joint affected the fracture behavior of samples in the three directions.

关 键 词：Friction stir welding Dissimilar joint TEXTURE ANISOTROPY Tensile properties 

分 类 号：TG453.9[金属学及工艺—焊接]