6063铝合金单模光纤激光焊接工艺研究

Single-Mode Fiber Laser Welding Process of 6063 Aluminum Alloy

目的针对采用脉冲激光点焊的6063铝合金焊点拉力较低,无法满足实际需求的问题,研究6063铝合金激光焊接的最优工艺方案,以提升焊点拉力。方法采用单模光纤激光对6063铝合金进行焊接,通过极细的线宽组成螺旋点,代替单个脉冲激光点焊。对激光功率、焊接速度及离焦量等工艺参数进行正交实验,得到最佳工艺参数,并通过分析焊缝外观与微观组织,解释焊点拉力提升的原因。结果当激光功率为70 W,焊接速度为100 mm/s,离焦量为0时,焊点拉力达到最大的65 N,此时的工艺参数为最佳工艺参数。6063铝合金单模激光焊点拉力是脉冲激光焊点拉力的3倍。结论单模光纤激光螺旋线焊接时,激光能量在光斑范围内均匀分布,且有较大的功率密度,形成焊缝表面与焊缝底部宽度几乎一致的焊缝形状,有利于提高焊点拉力,为实际生产提供技术参考。

The work aims to study the optimum laser welding process scheme for 6063 aluminum alloy to improve the tension of welding spot in view of that the tension of 6063 aluminum alloy spot-welded by pulse laser is low and fails to meet the actual needs. The single-mode fiber laser was used to weld 6063 aluminum alloy, and the spiral spots were formed by extremely fine line to replace single pulse laser spot welding. The orthogonal experiment was carried out to laser power, welding speed and defocus to obtain the optimum parameters. Through the analysis on the appearance and microstructure of the weld, the reason for the increase of the welding spot tension was explained. When laser power was 70 W, welding speed was 100 mm/s, and defocus was 0, the tension of spots reached the maximum 65 N, and the process parameters were the best. The tension of single-mode laser welding spot was 3 times that of pulse laser welding spot. In welding with single-mode fiber spiral laser, the laser energy is evenly distributed in the spot range and has a large power density, forming a weld shape with the weld surface width almost the same as that of the weld bottom, which is conducive to improving the tension of welding spot and providing technical reference for actual production.