超声辅助被动填充搅拌摩擦修复研究

Study on Ultrasonic Assisted Passive Filling Friction Stir Repairing

搅拌摩擦焊焊后残留的匙孔会极大地降低焊缝力学性能,对其进行修复具有重要的工程意义。以AZ31B镁合金为对象,对比研究了超声加入对被动填充搅拌摩擦修复工艺的影响。结果表明:与未加入超声相比,超声可以减小飞边、促进材料流动、增加原子扩散能力,进而获得无缺陷的修复接头;采用超声辅助被动填充搅拌摩擦修复工艺的修复接头抗拉强度达到182.9 MPa;与未加入超声的工艺相比,修复接头拉伸强度提高38%。同时,超声辅助被动填充搅拌摩擦修复接头的断口形貌有大量韧窝,为典型的韧性断裂。

The residual keyhole after friction stir welding can reduce the mechanical properties of the joint, and the repairing of the keyhole has an important engineering significance. Taking AZ31B magnesium alloy as the object, the effect of adding ultrasonic on the passive filling friction stir reparing(PFFSR) process was studied. The results show that compared with the process without ultrasonic, the flash is reduced, material flow is increased and atomic diffusion is strengthened by ultrasonic, the defect-free joint is obtained;the tensile strength of the joint with ultrasonic assisted PFFSR reaches 182.9 MPa,which is increased by 38% compared with that of the joint without ultrasonic. Moreover, the fracture morphology of ultrasonic assisted PFFSR joint has a large number of dimples, which is typical ductile fracture.