对7N01铝合金薄板进行正反面各一道次的双面搅拌摩擦焊（FSW），研究了接头的显微组织、硬度分布、拉伸性能和应力腐蚀敏感性。结果表明：FSW接头成形良好，焊核区为均匀细小的等轴晶组织，正反焊道交界处焊核区由于受到两次热-力耦合作用，晶粒较其他焊核区的细小，热力影响区晶粒发生剪切变形，呈条弧状，热影响区晶粒呈原始板条状；从焊核区到母材，硬度逐渐降低，正反焊道交界处的焊核区硬度高于其他位置焊核区的；在空气和质量分数3.5% NaCl溶液中，FSW接头均在热影响区断裂，热影响区为薄弱区；与母材相比，接头拉伸性能较差，应力腐蚀敏感性较高。

The double-sided friction stir welding was performed on 7N01 aluminum alloy sheet, in the mode of front side and back side welding for one pass each. The microstructure, hardness distribution, tensile properties and stress corrosion susceptibility of the joint were studied. The results show that the FSW joint was well formed. The weld nugget zone had a uniform and fine equiaxed crystal structure and the grains of the weld nugget zone at junction of weld beads were smaller than other weld nugget zones due to secondary thermo-mechanical couple effects. The grains in the thermal mechanically affected zone underwent shear deformation and showed a strip shape. The grains of the heat affected zone showed an original lath shape. The hardness decreased gradually from the weld nugget zone to base metal, and the hardness of the weld nugget zone at junction of weld beads was higher than that of other weld nugget zones. FSW joints fractured in the heat affected zone in air and 3.5wt% NaCl solution, indicating the heat affected zone was the weakest. The tensile properties of the joint were lower than those of the base metal, and the stress corrosion susceptibility was higher.