激光焊接技术具有单位热输入量少、热变形小、焊缝深宽比大、焊接速度高、可焊接复杂结构件、易于实现远程焊接和自动化等明显优势, 在汽车制造中得到广泛应用。本文分析了预置填充稀土粉末对1 mm厚6061铝合金激光焊接组织和性能的影响。试验表明, 直接焊接的焊缝平均显微硬度为44.5 HV, 填充稀土粉末的焊缝平均显微硬度为50.1 HV, 达到母材硬度的83.1%; 但稀土含量过高容易促进焊缝氢气孔的产生, 使得焊缝硬度分布不均匀; 降低焊缝的抗拉强度, 未填充稀土粉末的焊缝平均抗拉强度为111.04 MPa, 达到母材的89.5%, 而填充稀土粉末的焊缝平均抗拉强度为89.06 MPa, 仅为母材的71.8%。

Laser welding technology has the advantages of low heat input, small thermal deformation, high depth-to-width ratio, high welding speed, being able to weld complicated structure, being easy to implement remote welding and automation etc. It is widely used in automotive manufacturing. This investigation analyzes the microstructure and mechanical properties of the laser welded 1 mm thick 6061 aluminum alloy with and without filling rare earth powder. Results indicate that the average microhardness of the directly welded joint is 44.5 HV, while that of the filling powder weld is 50.1 HV, which is 83.1% of the base material. But it is prone to promote the generation of hydrogen porosity if the rare earth content is too high, resulting in the nonuniform distribution of the microhardness and the reduction in the weld tensile strength. The average tensile strength of the weld without filling rare earth powder is 111.04 MPa, 89.5% of the base material. But the average tensile strength of the weld with filling rare earth powder is 89.06 MPa, 71.8% of the base material.