激光功率对6061-T6铝合金激光填丝焊接头组织及性能的影响

采用激光填丝焊将厚度为2 mm和3 mm的6061-T6铝合金板材进行搭接叠焊，研究激光功率对接头成形质量的影响，分析了接头的显微组织和力学性能。结果表明，增大激光功率可以有效增加热输入量，焊道逐渐宽化，焊缝熔深增加。进一步分析发现，焊缝中心区和热影响区的析出相均为Mg₂Si。硬度试验结果表明，焊缝中心区由于细小等轴晶和析出相的双重作用，硬度远高于母材区与热影响区的。拉伸试验结果表明，接头的抗拉强度随激光功率的增大而升高，激光功率由2.0 kW升高至2.8 kW，抗拉强度升高约39%。

Effect of laser power on the microstructure and properties of 6061-T6 aluminum alloy laser wire filling welded joint

The 6061-T6 aluminum alloy sheets with thickness of 2 mm and 3 mm were lap welded by laser wire filling welding, the effect of laser power on the forming quality of joint was studied, and the microstructure and mechanical properties of joint were analyzed. The results show that increasing laser power can effectively increase the heat input, gradually widen the weld pass, and deepen the weld penetration. Further analysis indicates that the precipitated phases in weld center zone and heat affected zone are Mg₂Si. The hardness test results show that the hardness of the weld center zone is much higher than that of the base material and heat affected zones due to the double actions of fine equiaxed crystal and precipitated phase. The tensile test results show that the tensile strength of joint increases with the increase of laser power. With the laser power increased from 2.0 kW to 2.8 kW, the tensile strength increases by about 39%.