【摘要】 采用直径为1.2 mm的ER4043焊丝，通过不同TIG熔钎焊工艺，实现了5A02铝合金和Q235钢异种接头有效连接。通过使用金相显微镜（OM）、扫描电镜（SEM）和能谱仪（EDS），观察熔钎焊接头宏观形貌、界面特征。结果表明，未涂覆金属粉末的接头试样在焊缝区出现晶间裂纹，预置涂覆金属粉末试样焊缝成形性能优于未涂覆金属粉末的试样；铝合金侧热影响区受热后晶粒有粗大倾向，焊缝区组织为α-Al等轴晶和Al-Si共晶组织，Al-Si共晶均匀分布在α-Al晶界上；界面区附近Al和Fe原子沿着界面层相互扩散，形成多种Fe-Al金属间化合物，靠近钢侧主要为FeAl化合物，靠近铝侧以FeAl₃化合物为主。更多还原

【Abstract】 ER4043 welding wire with a diameter of 1.2 mm was selected to achieve effective connection of dissimilar joints between 5A02 aluminum alloy and Q235 steel through different TIG melt-brazing processes. The macro morphology and interfacial characteristics of brazed joint were observed by metallographic microscope（OM）, scanning electron microscope（SEM） and energy dispersive spectrometer（EDS）. The results indicate that intergranular cracks are observed in the fusion zone of joint specimens without metal powder coating, and the weld formation of specimens pre-coated with metal powder is superior to that of ones without metal powder coating. The heated grains in the heataffected zone on the aluminum alloy side tend to coarsen. The weld zone is composed of α-Al equiaxed grains and AlSi eutectics structure, and the latter one is uniformly distributed on α-Al grain boundaries. Al and Fe atoms near the interface region are diffused along the interface layer, leading to various Fe-Al intermetallic compounds, where FeAl compounds are generated near the steel side, and FeAl₃ compounds are generated near the aluminum side.更多还原