利用圆柱螺纹和三棱柱螺纹搅拌头对2024-T3与7075-T6铝合金进行了搅拌摩擦对接焊, 并对焊缝的宏观形貌、硬度以及接头的拉伸性能、断口形貌进行了分析。结果表明: 搅拌头转速为1 100 r·min-1和焊接速度为80 mm·min-1时的焊缝中无隧道类缺陷, 且三棱柱螺纹搅拌头使得两种材料融合得较好, 搭配方式为AS(2024)-RS(7075)的接头抗拉强度达到了260 MPa, 断裂位置为2024-T3铝合金的TMAZ区; 搅拌头转速为1 100 r·min-1和焊接速度为120 mm·min-1且搭配方式为AS(2024)-RS(7075)时, 圆柱螺纹搅拌头对应焊缝的硬度最小, 仅为107 HV, 且拉伸断口上的韧窝数量最少、深度最浅, 抗拉强度也最低, 为78 MPa。

Friction stir welding was conducted on 2024-T3 and 7075-T6 aluminum alloys with threaded cylindrical and threaded triangular prism stir heads, and the macrograph and hardness of the weld seam, tensile properties and tensile fracture morphology of the joint were analyzed. The results show that there was a good fusion in the weld seam without any tunnel defects welded with threaded triangular prism stir head under the parameters of 1 100 r·min-1 and 80 mm·min-1, which made the tensile strength of the joint with material collocation method of AS(2024)-RS(7075) reached 260 MPa and fractured in the thermal-mechanically affected zone (TMAZ) area of 2024-T3 alloy; the minimum hardness of 107 HV appeared in the joint welded with threaded cylindrical stir head under the parameters of 1 100 r·min-1 and 120 mm·min-1 and material collocation method of AS(2024)-RS(7075), fewer and shallower dimples reduced its tensile strength to the minimum of 78 MPa.