光纤激光焊接A356铝合金过程气孔敏感性（英文）

发布时间：2019-03-13 18:23

【摘要】：为减少激光深熔焊接铝合金过程中产生的冶金型气孔和小孔型气孔,达到提高工件力学性能的目的,系统分析激光功率、焊接速度以及离焦量等工艺参数分别对两种气孔造成的影响,同时观察不同焊接参数下小孔上方的金属蒸汽羽烟形状与波动情况,以反映焊接过程中小孔的稳定性。结果显示,增加激光功率或减小激光光斑半径时,小孔上方金属蒸汽羽烟波动剧烈,形状和大小都极不稳定,间接反映小孔的稳定性更差,因此在焊缝根部产生更多小孔型气孔。当由激光能量密度变化引起的小孔深宽比增高时,小孔内部坍塌的可能性升高,并在焊缝中留下更多的气孔。当激光功率为5 k W、离焦量为0、焊接速度为2.0 m/min时,气孔率达到最小值。
[Abstract]:In order to reduce the metallurgical pores and small pores produced in the process of laser deep penetration welding of aluminum alloy, and to improve the mechanical properties of the workpiece, the laser power is analyzed systematically. The effects of welding speed and defocus on the two kinds of pores were observed, and the shape and fluctuation of metal vapor plume above the holes were observed under different welding parameters to reflect the stability of the holes in the welding process. The results show that when the laser power is increased or the laser spot radius is reduced, the metal vapor plume above the hole fluctuates violently, and its shape and size are extremely unstable, which indirectly reflects that the stability of the small hole is worse. As a result, more pore holes are produced at the root of the weld. When the depth-to-width ratio of the holes is increased due to the change of laser energy density, the possibility of the holes collapsing inside the holes increases, and more holes are left in the weld. When the laser power is 5 kW, the defocus is 0, and the welding speed is 2.0 m/min, the porosity reaches the minimum value.
【作者单位】：上海交通大学材料科学与工程学院;上海交通大学上海市激光制造与材料改性重点实验室;
【基金】：Project(51204109)supported by the National Natural Science Foundation of China
【分类号】：TG456.7

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