7050-T7451铝合金搅拌摩擦焊接头组织和性能

Microstructure and Properties of Friction Stir Welding 7050-T7451 Aluminum Alloy

在不同焊接工艺参数下对3.5 mm厚的7050-T7451铝合金进行了搅拌摩擦对接焊,并对焊缝成形质量、接头微观组织演变和拉伸性能进行了深入研究。结果表明,当搅拌头旋转速度(ω)在400~1000 r/min、焊接速度(v)在50~300 mm/min时,均可获得内部无缺陷的接头。当焊接速度不变时,随搅拌头旋转速度的增加,接头的拉伸性能先增大后减小。当搅拌头旋转速度为600 r/min、焊接速度为150 mm/min时,接头的拉伸性能最好,抗拉强度为475 MPa,强度系数达90%,伸长率为5.7%。当ω/v的值处于4~6之间时,可获得拉伸性能优良的接头。

3.5 mm thick 7050-T7451 aluminum alloy was friction stir butt welded at various welding parameters.The forming quality of weld,microstructure evolution and tensile properties of the welded joints were studied in detail.The results show that the joint without internal defects can be obtained when the rotational speed(ω)is in the range of 400—1000 r/min and the welding speed(v)is in the range of 50—300 mm/min.When the welding speed is constant,the tensile properties of the joints increase and then decrease with the increase of the rotating speed.When the rotation speed is 600 r/min and the welding speed is 150 mm/min,the tensile strength of the joint is 475 MPa,the strength coefficient is 90%and the elongation is 5.7%.When the value ofω/v is between 4 and 6,the joints with good tensile properties can be fabricated.