采用板条CO2激光器对铝钢异种金属搭接接头进行激光填丝焊接试验研究。分析了不同热输入量对焊缝成形质量的影响以及不同热输入量对焊缝显微组织、焊缝物相及力学性能的影响。实验结果表明，与低能量密度参数下的焊接接头相比高能量密度参数下的焊缝内部组织将不再均匀，而是出现了条状或块状金属间化合物FeAl，铝铁界面产生的金属间化合物厚度增加，钢板熔化区主要物相也由低能量密度时的FeAl和Al与α-Fe形成的固溶体转变为Fe3Al和Al与α-Fe形成的固溶体，从而降低了焊缝的力学性能。拉剪结果显示，高能量密度焊接参数下的焊缝抗拉（剪）强度仅为低能量密度下的72.9%。

Dissimilar metal joining of steel/aluminum alloy by slab CO2 laser beam welding with filling wire is investigated and the influence of different heat input on the weld formation quality is introduced. The influence of different heat input on microstructure, phase and mechanical properties of joints are analyzed. The experimental results show that microstructure in the joints with higher heat input parameters compared with lower heat input parameters is no longer homogenous, Fe-Al intermetallic phase with the shape of strip and lump can be found in the joints, the thickness of the intermetallics layer increases in the interface of aluminum/steel joints, and the main phase in the melts of joints transforms from FeAl and solid solution of Al in α-Fe to Fe3Al and solid solution of Al in α-Fe. Mechanical properties deteriorate with the increase of the intermetallics layer. Tensile test shows that tensile (or shear) strength with high heat input parameters is 72.9% of that with low heat input parameters.