排布方式对铝合金激光-MIG复合横向焊接特性的影响

采用常规激光-熔化极惰性气体保护电弧(Metal inert gas,MIG)复合横向焊接铝合金过程中,焊缝表面极易出现咬边和下塌等缺陷,由此开展排布方式对激光-MIG电弧复合横向焊接铝合金焊接特性的影响研究。分析二者的排布方式对熔池特征、熔滴过渡形式以及焊缝成形规律的影响。试验结果表明,异面引导复合焊接方式对焊缝成形有明显改善作用,焊缝表面熔宽减少、中心线偏移和咬边缺陷得到有效抑制。采用同面引导复合方式时,熔滴过渡到匙孔后方,熔池下侧熔融金属大量堆积并产生周期性的波动,导致焊缝结晶组织出现了分层现象;而采用异面引导复合方式时,熔滴过渡到匙孔下方,并且熔滴在熔池中的落点位置与同面引导方式相比要偏上,熔滴过渡频率稍低,此时熔池中熔融金属分布较为均匀,熔池下部堆积金属较少,有效抑制了焊缝的下塌和咬边缺陷。

Influence of Arrangement on Laser-MIG Hybrid Horizontal Welding Characteristics of Aluminum Alloy

Aiming at thedefects such as undercut and collapse on weld seam surface in the conventional laser-metal inert gas(MIG) hybrid horizontal welding process of aluminum alloy, study upon the characteristics of different arrangements on laser-MIG hybrid horizontal welding of aluminum alloy is conducted.The experimental results show that,non-coplanar leading hybrid welding could reduce the weld width, improve the weld formation and effectively suppress the centerline deviation and undercut defect. When adopting the coplanar arrangement hybrid welding,the droplet transferred into the rear of keyhole, and the accumulation of the molten metal appearing in the lower areas of the pool with periodic fluctuation resulted in the stratification of weld solidification structure. However, when adopting the non-coplanar arrangement way,the droplet transferred below the keyhole and the landing position of droplets in the molten pool was above the coplanar leading way. In addition, the droplet transition frequency is slightly lower, which lead to a more uniform distribution of molten metal in the molten pool, and the accumulation metal in the lower areas decreased, effectively suppressing the undercut and collapse defects.