LF6铝合金双光束激光点焊工艺研究

Laser spot welding of LF6 aluminum with double laser beams

以LF6铝合金为实验材料,进行了双光束激光点焊实验,对比了双光束激光点焊接头与普通单光束激光点焊的接头,并且研究了激光功率、点焊持续时间、能量比等对点焊接头形貌和熔合面尺寸的影响。实验结果表明:在相同的功率下,双光束点焊增大了匙孔的直径,提高了匙孔的稳定性,与单光束激光点焊相比,焊点内部气孔数量大大减少,并且熔合面尺寸有了很大的提高;当激光功率不同时,焊点的上表面尺寸变化差距不大,小功率条件下焊点呈"钉状";双光束激光的能量比会影响焊点表面的下榻量,能量比为1:1的情况下焊点的下塌量要明显小于能量比为1.5:1的情况。

Experiment of laser spot welding of LF6 aluminum with double laser beams was carried. The cross-section of laser spot welding joints with single laser beam and double laser beams were compared, and the effects of laser power, pulse duration and power ratio on the weld joint dimension were investigated. The experimental results indicate that when the power is fixed, the double laser beams can increase the keyhole diameter and improve the stability of the keyhole, decreasing the number of pores, increasing the dimension of fusion area. It is discovered that the dimension of top sheet′s change is small, when the laser power changes. And the area of weld joint in the bottom sheet is smaller than that in the top sheet when the laser power is low. At the same total input power, the crater depth with the laser power ratio 1：1 is much smaller than that of laser power ratio 1.5：1.