采用响应曲面法对2A12铝合金激光封边焊接进行了研究，结果表明，2A12铝合金激光封边焊接焊缝几何特征的主要影响因素依次为离焦量、焊接速度和激光功率. 2A12铝合金激光封边焊缝的显微组织自熔合线向上依次呈现较粗大的胞状树枝晶、细小的胞状树枝晶和等轴晶. 在熔合线附近和过渡区域，强化相沿晶界分布；而在焊缝中心区域，还有少量强化相分布于晶粒内部. 与正离焦量相比，负离焦量时，焊缝的晶粒尺寸较大并且镁元素烧损也更加严重，使得强化相CuMgAl2含量降低，导致强化效果减弱和焊缝硬度降低. 离焦量为 + 2 mm和−2 mm时，激光封边焊接的气密性均良好.
Response surface methodology was used to study the laser edge sealing welding of 2A12 aluminum alloy. The results showed that the main influencing factors of the geometrical characteristics of 2A12 aluminum alloy were defocusing amount, welding speed and laser power. From fusion line to weld center, the microstructure of 2A12 aluminum alloy laser edge sealing weld were coarse cellular dendrites, fine cellular dendrites and equiaxed crystals. The strengthening phases distributed along the grain boundary near the fusion line and in the transition region. At the center of weld, a small amount of strengthening phases distributed in the grain. Compared with the positive defocusing amount, the grain size of weld was larger and the magnesium element burned more seriously at the negative defocusing amount, which reduced the content of strengthening phase CuMgAl2 and led to the weakening of strengthening effect and the reduction of weld microhardness. When defocusing amount were + 2 mm and −2 mm, both of the air tightness of laser edge sealing welding were good.
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