2A12-T4/7A09-T6铝合金搅拌摩擦焊搭接接头性能分析

Study on friction stir lap weld of 2A12-T4/7A09-T6 aluminum alloys

采用不同的搅拌摩擦焊工艺参数对1.2 mm 2A12-T4铝合金搭接4.0 mm 7A09-T6铝合金板材进行焊接试验,对焊后试样进行力学拉伸检测并对焊缝横截面进行微观组织观测.结果表明,搅拌针从厚板插入薄板的接头力学性能高于从薄板插入厚板,当转速达到800 r/min、焊接速度达到400 mm/min时,焊接接头的抗拉伸载荷达到最高的17 kN,达到薄板2A12-T4铝合金母材的85%.在焊接速度不变的情况下,随着转速的提升,焊缝横截面的界面曲线长度缩短,而界面长度曲线越短,接头力学性能越好.试样断口全部出现在薄板一侧的焊缝起始端,断裂机制为混合断裂.

The 1.2 mm 2A12 was friction stir lap welded with 4.0 mm 7A09 aluminum alloys in different welding parameters.Specimen were subjected to tensile testing and observed by metallographic.The results showed that tensile force of joint was higher when the thick plate up to the sheet one.The maximum tensile strength of 17 kN,account for 85%of parent metal,as rotation and welding speed set as 800 and 400 mm/min.Tensile force was increasing with reduce of interface boundary in intersecting surface of joint.All the fractures were appeared at the beginning of weld joint on sheet plate,showing mixed fracture.