2219铝合金FSW/VPPA交叉焊缝气孔缺陷

2219铝合金在搅拌摩擦焊（FSW）后，进行变极性等离子弧焊（VPPA）十字交叉焊接，其交叉接头存在气孔缺陷.针对6 mm 2219铝合金进行FSW/VPPA交叉焊接试验，探究了交叉焊缝的气孔类型，分别对比不同FSW热输入量、不同的VPPA焊接速度对交叉焊缝气孔缺陷程度的影响.结果表明，FSW热输入量越大，交叉焊缝气孔缺陷程度呈下降趋势，这与FSW过程产生瞬时空腔有关；而VPPA焊速越大，交叉焊缝气孔缺陷程度呈上升趋势.因此，为了抑制FSW/VPPA交叉焊缝气孔的产生，可以对FSW过程进行惰性气体保护、适当地提高FSW热输入量以及降低VPPA焊接速度.

Porosity defects of 2219 aluminum alloy intersection weld by FSW and VPPAW

FSW-VPPA intersection weld on 2219 aluminum of 6 mm in thickness was perpendicularly conducted by friction stir welding (FSW) and variable polarity plasma arc (VPPA) welding and it is found that there are porosity defects in cross-connectors. Therefore, porosity defects of 2219 aluminum alloy intersection weld by FSW and VPPA were analyzed to determine the type of porosities. The effects of welding parameters such as FSW heat input and VPPA welding speed on the porosity defects were compared and analyzed. The results show that the degree of porosity defects of cross-weld joint decreases with the FSW heat input being increased, which is due to the transient cavity formed in the FSW process. However, the degree of porosity defects of cross-joint increases with VPPA welding speed being increased. In order to reduce the degree of porosity defects of cross-joint, some measures had been taken, such as insert gas shielding, increase of the FSW heat input and reduction of VPPA welding speed appropriately.