For hybrid laser-MIG welding of aluminum alloy, the weld bead quality is decided by the thermal dynamics in the molten pool. In order to analyze the influence of leading configuration on thermal behavior and mass transfer, a three-dimensional numerical model is established. In the model, a combined model is utilized to simulate the multiple reflections and Fresnel absorption of laser beam. The laser-arc interaction is considered and the plasma is shrinked for arc-leading configuration. Surface tension, electromagnetic force, buoyancy are considered to investigate the fluid flow pattern, and droplet impact and arc pressure are taken into account to track the free surface. For different configurations, the temperature and velocity field, together with concentration distribution of magnesium and zinc are compared and analyzed. The results show that transport phenomena of the molten pool is strongly affected by the configuration. For arc-leading (AL) configuration, it is easier to get a larger penetration. Meanwhile, the concentration distribution of magnesium and zinc is more homogeneous for laser-leading (LL) configuration. Furthermore, the developed model can provide theoretical basis for processing experiments.

对于铝合金的混合激光-MIG焊接，焊缝质量取决于熔池中的热力学。为了分析主导构型对热行为和传质的影响，建立了三维数值模型。在该模型中，利用组合模型来模拟激光束的多次反射和菲涅耳吸收。考虑了激光-电弧相互作用，并且缩小了等离子体以形成超前电弧配置。考虑表面张力，电磁力，浮力来研究流体的流动方式，并考虑液滴的撞击和电弧压力来跟踪自由表面。对于不同的配置，对温度和速度场以及镁和锌的浓度分布进行了比较和分析。结果表明，熔池的输送现象受构型的强烈影响。对于引弧（AL）配置，更容易获得更大的穿透力。同时，对于激光引导（LL）配置，镁和锌的浓度分布更加均匀。此外，所建立的模型可以为加工实验提供理论依据。