中国激光, 2012, 39 (12): 1203001, 网络出版: 2012-10-25
间隙对5754铝合金激光填丝搭接焊气孔的影响
Effects of Gap on Porosity during Laser Lap Welding with Filler Wire of Al 5754 Sheets
摘要
气孔是5754铝合金激光搭接焊接过程中经常出现的缺陷,它对焊缝的机械性能有很大的影响。实验采用光纤激光器研究了在搭接铝合金板间设置间隙对气孔的影响及其机理,发现,间隙的设置为气孔的逃逸提供了一个通道,气孔率有明显减小的趋势。当间隙从0变化到0.2 mm时,由于间隙较小而有毛细现象的发生,搭接间隙气孔的逃逸通道被液态焊缝金属的凝固过程封闭,气孔减小并不明显;当间隙从0.30 mm变化到0.75 mm时,由于间隙增大,间隙部位的焊缝液态金属发生的毛细现象减弱甚至消失,导致这部分金属距离熔合线很近,表面保持液态,气孔逃逸的通道被打开,气孔有明显减小的变化。实验还发现,随着间隙的增大,搭接焊缝的剪切强度有了很大的提高。
Abstract
Defect of the porosity always occurs during laser welding of 5754 aluminum alloy and has a lot of bad influence on its mechanical property. Effects of the gap between two lap welding sheets on the porosity have been studied using fiber laser to weld 5754 aluminum alloy. It is found that setting a proper gap between two sheets can provide a passage for the escape of the porosity and decrease the porosity rate. When the gap changes from 0 to 0.2 mm, because of the capillary phenomenon, the escaping passage is closed by the solidification of the liquid weld metal, and the porosity decreases little. When the gap changes from 0.30 mm to 0.75 mm, the capillary phenomenon of the liquid weld metal between the gap weakens. So this part of weld metal is close to the fusion line and keeps liquid state. Then the escaping passage is opened and the porosity decreases obviously. It is also found that as the gap increases, the shear stress increases a lot.
王国振, 王春明, 王军, 杨上陆, 胡席远. 间隙对5754铝合金激光填丝搭接焊气孔的影响[J]. 中国激光, 2012, 39(12): 1203001. Wang Guozhen, Wang Chunming, Wang Jun, Yang Shanglu, Hu Xiyuan. Effects of Gap on Porosity during Laser Lap Welding with Filler Wire of Al 5754 Sheets[J]. Chinese Journal of Lasers, 2012, 39(12): 1203001.