铝合金中厚板高功率激光搅拌焊气孔缺陷工艺调控

高功率激光焊接为铝合金中厚板高质高效焊接提供了有效手段，然而面临焊缝气孔多发的问题. 文中开展了铝合金中厚板高功率激光搅拌焊接气孔缺陷的工艺调控研究，阐明了搅拌振幅和搅拌频率对接头气孔率的影响，并提出了工艺参数优化方法. 结果表明，搅拌振幅主要影响光束运动轨迹横向分布和小孔开口面积；搅拌频率主要影响激光光束运动速度和对后方熔池的搅拌次数；搅拌振幅和频率越大，气孔抑制效果越明显，但焊缝熔深难以满足应用要求；通过控制光束运动轨迹和能量密度，可以实现工艺参数的设计，获得大熔深、少气孔的最佳工艺区间，最终得到熔深高达6.4 mm的少气孔焊接接头.

Process control of the porosity defects in high power oscillating laser welding of medium-thick aluminum alloy plates

High power laser welding provides an effective method for high-quality and high-efficiency welding of medium-thick aluminum alloy plates, but the porosity defects are prominent. In this study, a research on the process control of the porosity defects during high power oscillating laser welding of medium-thick aluminum alloy plate is carried out. Particularly, the influence of oscillating amplitude and frequency on the porosity of joints is clarified. Moreover, a welding parameter optimizing method is proposed. The results show that the oscillating amplitude mainly affects the lateral distribution of the beam movement trajectory and the aperture area of the keyhole, while the oscillating frequency mainly affects the laser beam movement speed and the number of oscillating times to the rear molten pool. The porositiy decreases as the oscillating amplitude and frequency increases, the weld penetration, however, is difficult to meet the requirements. The correlation of the process parameters, laser power, oscillating frequency, oscillating amplitude and welding speed can be established by controlling the beam movement trajectory and energy density, and the best process interval with large penetration and less porosity can be obtained. Finally, a weld with less porosity was obtained, and the penetration depth reaches 6.4 mm.