2060铝锂合金电流辅助激光填丝焊接工艺分析

Electrical current assisted laser welding of 2060 aluminum-lithium alloy with filler wire

关键词:  铝锂合金  激光焊接  电流  焊缝成形  组织性能

Key words:  Al-Li alloy  laser welding  electrical current  weld formation  solidification microstructure and properties

摘要:

为了改善2060铝锂合金激光填丝焊接的焊缝组织并进一步提高接头力学性能，使用了辅助激光填丝焊接的新方法.文中采用光纤激光器焊接2 mm厚2060-T8铝锂合金薄板，通过填充焊丝引入直流电流，研究电流对焊缝成形、焊缝结晶组织和接头力学性能的影响.结果表明，施加电流后，焊缝表面鱼鳞纹变得细密均匀，表明焊接过程更加稳定.同时，焊缝上、下熔宽趋于一致，焊缝结晶组织细化，熔合线附近等轴细晶区宽度减小.与无辅助电流相比，接头抗拉强度提高约5.8%.

Abstract:

In order to improve the weld structure of 2060 Al-Li alloy laser weld and further improve the mechanical properties of the joints, a new method named current-assisted laser welding was used. In this paper, the effect of an additional direct current on the weld formation, solidified structures and joint mechanical properties were investigated in fiber laser welding of 2060-T8 Al-Li alloy thin sheet with 5087 filler wire. The electrical current was introduced into the weld pool through thefiller wire.It was found that the bead ripples become much finer with theaddition of direct current, indicating that the stability of the welding process was improved. The equiaxed dendrites were slightly refined in the weld and thethickness of the equiaxed grain zone (EQZ)near the fusion line was reduced. The tensile strength of the welded joints increases about 5.8% compared to that of the laser welded joint without assisting current.