工艺参数对AA2524回填式搅拌摩擦点焊接头成形及力学性能的影响

目的 改善2 mm厚AA2524回填式搅拌摩擦点焊（RFSSW）接头的成形和力学性能。方法 采用不同扎入深度和不同转速进行焊接，焊后对接头的孔洞大小、套筒退出线上的裂纹长度和拉剪强度进行对比，获得扎入深度和转速对接头成形和拉剪强度的影响规律。结果 扎入深度为2.6 mm时，接头孔洞较小，断裂载荷较高。随着转速的增加，接头孔洞逐渐减小，套筒退出线的裂纹减少，拉剪强度逐渐升高。扎入深度2.6 mm，焊接时间6 s，转速为2600 r/min时，获得了无孔洞和无退出线裂纹的接头，断裂载荷最大，为9.4 kN。结论 合适的扎深和转速匹配，可以获得成形良好，高断裂载荷的接头。

Effect of Process Parameters on Formation and Mechanical Properties of AA2524 Refill Friction Stir Spot Welding Joints

The paper aims to improve the formation and mechanical properties of 2 mm thick AA2524 refill friction stir spot welding (RFSSW) joints. RFSSW was conducted at different plunge depth and rotational speed. The void size, crack length along the sleeve withdrawing path, and the tensile shear strength of the joints were compared. The effects of the plunge depth and rotational speed on the joint formation and tensile shear strength were obtained. When the plunge depth was 2.6 mm, the joint had smaller void and higher tensile shear strength. With the increase of speed, the voids of joint decreased gradually. At plunge depth of 2.6 mm, welding time of 6 s ant at 2600 r/min, joint without voids or cracks along the sleeve withdrawing path was obtained; and the fracture load was the maximum, which was 9.4 kN. A well-formed joint with high fracture load can be obtained by combination of appropriate plunge depth and rotational speed.