异种型号焊丝的铝合金变极性穿孔等离子弧焊缝的组织特征

Microsturture characterization of variable polarity plasma arc keyhole weld of aluminium alloy using dissimilar wire

采用ER4043焊丝作为填充金属,利用变极性穿孔等离子焊接技术制备了2A12铝合金穿孔焊缝,并通过外观和探伤检验了焊接质量。通过扫描电镜和透射电镜等观察并分析了焊缝组织与母材金属的差异,认为焊缝组织由焊丝和母材金属两者熔合而成,并且其强化相也由2种合金材料的强化相组成。在热影响区附近存在较窄的过时效区,并且热影响区内部强化相的改变都会造成焊缝在热影响区力学性能的下降。

2A12 aluminum alloy keyhole weld was manufactured with ER4043 welding wire by variable polarity plasma arc welding(VPPAW) techniques.The welding quality was checked with appearance and detection tests.The difference between parent metal and welding metal was analyzed by scanning electron microscope(SEM) and transmission electron microscope(TEM).It could be concluded that the welding metal and its strengthening phases were fused by filler metal and parent metal.The very narrow overaging area existed in the heat-affected zone(HAZ),and strengthening phases in HAZ were different with parent metal.All these would cause the decline of the mechanical properties of the weld.