6005A-T6铝合金型材双轴肩搅拌摩擦焊接头组织及力学性能

采用双轴肩搅拌摩擦焊接方法对4.5 mm厚6005A-T6铝合金型材在较高焊接速度下进行了对接试验。结果表明，较高的焊接速度下仍可获得外观及性能优良的接头，但易出现隧道型缺陷及裂纹缺陷。在试验参数下，接头性能与WP(焊接速度与搅拌头旋转速度的比值)有密切关系：接头抗拉强度随着WP值的增大基本呈现先增大后减小的趋势，在搅拌头转速为1 400 r/min以及焊接速度为1 400 mm/min时获得强度较高的接头，其抗拉强度为231 MPa，是母材强度的77%。断口扫描结果显示，在试验参数下，接头断裂方式随着WP值的增大由塑性断裂逐渐变为包含沿晶断裂、韧性断裂、解理断裂的混合型断裂。

Microstructure and mechanical properties of bobbin tool frication stir welded joint of 6005A-T6 aluminum alloy profiles

Bobbin tool frication stir welding butt welded joints were fabricated for 6005A-T6 aluminum alloy profiles with 4.5 mm thickness at higher welding speed. The results show that the welds are excellent both in appearance and properties, but it is more likely to form defects such as tunnel and crack. At the selected welding parameters, the properties of welds shows close relationship with the line energy density, its tensile strength increases with the increase ofWPand reached up to 231 MPa, 77% of the base metal strength at the welding parameters of 1 400 r/min and 1 400 mm/min. The fracture appearance analysis indicates that the fracture mode changes from mixed fracture to ductile fracture with the increase ofWP.