6061铝合金激光穿透焊的焊缝成形

Weld Appearance of 6061 Aluminum Alloy by Laser Beam Full Penetration Welding

分别采用光纤激光和YAG激光对2.5mm厚的6061铝合金开展了激光穿透焊接试验,研究了主要焊接参数对焊缝成形的影响规律。结果表明,与YAG激光相比,高能量密度的光纤激光更易于实现穿透焊接,且光纤激光获得良好焊缝成形的工艺区间更大。在穿透焊接条件下,焊缝截面形貌分为钉头形和近X形两种。当激光功率较高时,光纤激光焊缝更趋向于生成近X形截面,YAG激光焊缝更易于生成钉头形截面。焊缝成形受激光功率密度和焊接热输入双重因素的影响。随激光功率密度和焊接热输入的增大,光纤激光焊缝截面形貌逐渐由钉头形向近X形转变。

The welding experiments of 6061 aluminum alloy with 2.5mm thickness, are carried out by ifber laser beam and YAG laser beam. The effects of major welding parameters on weld appearance are investigated. The results show that the ifber laser beam with high energy density is easier to realize full penetration welding than YAG laser beam. And the processing tolerance （the good weld appearance could be obtained easily） of the former is also broader than that of the latter. When the joints are fully penetration welded, the cross-sections of the weld seams present two types of nail shape and near X shape. The weld with near X shape cross-section character is ten-dency to be obtained by ifber laser beam with high power, while the weld with nail shape cross-section character is helpful to be obtained by YAG laser. The weld appearance is influenced intensively by heat input and laser power density in welding. With heat input and laser power densi-ty increasing, the cross-section of weld by ifber laser bean transforms from nail shape to near X shape.