Abstract An oscillating electromagnetic field weld pool support system combined with a welding sample travel mechanism was designed for improving the weld bead formation in full-penetration laser welding of A5083 aluminum alloy. The experimental results show that a proper oscillating electromagnetic field can effectively reduce the weld root sagging. When the root mean square of magnetic induction intensity on the back surface Brms0 = 80 m T and its electromagnetic frequency f = 400 Hz, the weld root sagging for the joint of aluminum alloy plate with thickness of 10 mm can be almost eliminated. The electromagnetic frequency and the laser power have a great impact on the weld root sagging height and the weld back surface roughness, while the influence of magnetic induction intensity is relatively small within its variable range in this study. The analysis of welding joint microstructure shows that the electromagnetic field can also refine the grains to some extent and decrease the width of columnar grain zone, decreasing the cracking susceptibility and improving the mechanical properties of the welding joint. However, the undercut defects are inevitable in full-penetration laser welding of aluminum alloy unless filler wire is used, because the metallic evaporation and splash are unavoidable during the high-power laser welding process.

中文翻译：

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电磁场支持下铝合金全熔透激光焊接焊道特性

摘要 为改善A5083铝合金全熔透激光焊接焊道的形成，设计了一种结合焊接试样移动机构的振荡电磁场焊池支撑系统。实验结果表明，适当的振荡电磁场可以有效地减少焊根下垂。当背面磁感应强度的均方根Brms0 = 80 m T，其电磁频率f = 400 Hz时，10 mm厚铝合金板接头的焊根下垂几乎可以消除。电磁频率和激光功率对焊缝根部下垂高度和焊缝背面粗糙度有很大影响，而磁感应强度的影响在本研究的可变范围内相对较小。焊接接头显微组织分析表明，电磁场还可以在一定程度上细化晶粒，减小柱状晶区的宽度，降低裂纹敏感性，提高焊接接头的力学性能。然而，除非使用填充焊丝，否则在铝合金的全熔透激光焊接中，咬边缺陷是不可避免的，因为在大功率激光焊接过程中金属蒸发和飞溅是不可避免的。