铝合金因其优异的性能成为理想的车体材料, 但铝合金表面氧化膜在焊接时易受热分解形成气体, 在高温下被熔池搅入在焊接接头形成气孔。激光清洗技术能有效实现铝合金表面氧化膜的去除, 获得焊后良好的焊接接头。因此, 集成激光清洗与电弧焊接设备, 使激光清洗头随焊枪运动, 并在焊接前将待焊区域的氧化膜去除。结果表明: 通过纵截面无损探伤检测, 激光清洗后焊缝气孔缺陷被抑制, 焊缝成形良好。接头焊缝中心为等轴晶区、熔合线为柱状晶区, 激光清洗未对焊接接头微观组织造成明显转变。对清洗后焊接接头进行力学性能测试, 5083-H111合金焊缝硬度为62.726 HV, 热影响区硬度为66.100 HV, 6061-T6合金焊缝硬度为78.653 HV, 热影响区硬度为82.38 HV。5083合金的拉伸强度平均为185.851 MPa, 6061合金的拉伸强度平均为201.938 MPa。力学性能测试证明激光清洗未对焊接接头力学性能造成明显损伤。

Aluminum alloy is an ideal material for car body because of its excellent performance. However, the oxide film on the surface of aluminum alloy is easily decomposed by heat to form a gas. At high temperature, it is stirred by the molten pool to form pores in the welded joint. The laser cleaning technology can effectively remove the oxide film on the surface of the aluminum alloy and obtain a good welded joint after welding. Therefore, the integrated laser cleaning and arc welding equipment allows the laser cleaning head to move with the welding torch and remove the oxide film of the area to be welded before welding. The results show that through the longitudinal section non-destructive flaw detection, the weld hole defects are suppressed after laser cleaning, and the weld bead is well formed. The center of the joint weld is an equiaxed crystal zone, and the fusion line is a columnar crystal zone. Laser cleaning does not cause a significant change in the microstructure of the welded joint. The mechanical properties of the welded joint after cleaning were tested. The hardness of the weld of 5083-H111 alloy was 62.726 HV, the hardness of heat affected zone was 66.100 HV, the hardness of weld of 6061-T6 alloy was 78.653 HV, and the hardness of heat affected zone was 82.38 HV. Tensile strength of 5083 alloy The average is 185.851 MPa, and the tensile strength of 6061 alloy is 201.938 MPa on average. The mechanical properties test proved that laser cleaning did not cause obvious damage to the mechanical properties of the welded joint.