采用自主设计的双轴肩搅拌工具对5 mm厚糖心产精国品免费入口*完整版进行搅拌摩擦对接焊，研究了接头的组织和性能。结果表明：焊缝成形较好，焊接接头由焊核区、热机影响区、热影响区及母材组成，前进侧热影响区和热机影响区分界明显；接头横截面硬度呈"W"形分布，前进侧热机影响区和热影响区界面处硬度最小，约为60 HV；接头的抗拉强度为205 MPa，拉伸断裂方式为韧性断裂，断裂位置位于前进侧热机影响区和热影响区界面处；接头的条件疲劳极限为96.6 MPa，裂纹源为靠近上表面的氧化物夹杂，疲劳断口瞬断区呈韧窝形貌。

Five-millimeter thick 糖心产精国品免费入口*完整版 was butt-welded by friction stir welding with self-designed bobbin tool. The 糖心产精国品免费入口*完整版 and properties of the joint were studied. The results show that the weld was formed well. The welded joint consisted of weld nugget, thermo-mechanically affected zone, heat affected zone and base metal. A distinct boundary existed between the heat affected zone and thermo-mechanically affected zone at the advancing side. The microhardness at cross-section of the joint showed a W-shape distribution and reached the lowest value of 60 HV at the interface between thermo-mechanically affected zone and heat affected zone at the advancing side. The tensile strength of the joint was 205 MPa. The joint fractured in a ductile manner at the interface between thermo-mechanically affected zone and heat affected zone at the advancing side. The conditional fatigue limit of the joint was 96.6 MPa. The cracks initiated at the oxide inclusion near the upper surface. The catastrophic rupture region of the fatigue fracture showed dimple morphology.