CMT工艺及其热输入对Al-Cu合金焊缝成形和气孔的影响

采用四种冷金属过渡焊接工艺(CMT)分别在不同热输入水平下，使用ER2319焊丝进行AA2219-T851高强铝合金的平板堆焊成形，全面分析其焊缝成形和气孔分布特征。结果表明，常规CMT焊缝具有明显指状熔深特征，气孔缺陷严重并呈全焊缝分布状态；CMT-P焊缝母材熔化面积明显增加，气孔数量显著减少且在适当控制热输入时有助于消除气孔；CMT-ADV焊缝也具有指状熔深特征但熔深显著减小；CMT-PADV焊缝具有显著球形熔滴成形特征且熔深最小，两工艺低热输入和对焊丝表面氧化膜的清理作用有助于消除气孔。

Influence of Cold Metal Transfer Process and Its Heat Input on Weld Bead Geometry and Porosity of Aluminum-Copper Alloy Welds

Weld bead geometry and porosity of AA2219-T851 high strength aluminum alloy welds with ER2319 wire produced by different cold metal transfer (CMT) processes and its heat input were investigated. The results show that, a narrow finger-shaped geometry is observed using the conventional CMT process and a large number of gas pores exist in the lower and upper part of welds. Compared to that of CMT process, the weld melting area is increased using CMT-P process, and it is beneficial to reduce the porosity effectively with an appropriate heat input. Finger-shaped geometry with lower melting depth using CMT-ADV process and spherical-shaped bead geometry with lower dilution using CMT-PADV process is achieved, respectively. The gas pore is reduced predominantly and even eliminated due to the lower heat input and effective oxide cleaning of wire ends for the two processes.