激光清洗预处理对7A52铝合金激光焊缝成形质量的影响  

Effect of Laser Cleaning Pretreatment on Laser Welding Formation of 7A52 Aluminum Alloy

作　　者：董世运[1,2] 宋超群[1,2] 闫世兴[1] 徐滨士[1] 何鹏[2] 

机构地区：[1]装甲兵工程学院装备再制造技术国防科技重点实验室,北京100072 [2]哈尔滨工业大学先进焊接与连接国家重点实验室,黑龙江哈尔滨150001

出　　处：《装甲兵工程学院学报》2017年第4期100-105,共6页Journal of Academy of Armored Force Engineering

基　　金：国家重点研发计划基金资助项目(2016YFB1100205);北京市科技专项基金资助项目(Z161100004916009;Z161100001516007)

摘　　要：为了探索激光清洗技术用于铝合金激光焊前预处理的可行性,在7A52铝合金试样表面进行了激光清洗预处理,并采用ER 5356铝合金焊丝在试样表面制备了激光填丝焊缝,分析了激光清洗后试样表面的形貌和成分特征,研究了激光清洗预处理对激光焊缝成形质量的影响规律。结果表明:激光清洗预处理后,试样表面存在波纹状的微沟槽织构,表面粗糙度由未预处理前的0.82μm增加至3.21μm,表面氧元素质量分数仅为2.44%;焊前激光清洗能够有效去除试样表面的原始氧化膜,降低焊缝内工艺气孔和氢气孔的产生倾向,并增加表面对激光的吸收率,改善熔滴在表面的铺展润湿性,从而提高焊缝的成形质量。激光清洗技术可适用于铝合金激光焊接前的表面预处理。To explore the practicability of laser cleaning technique as a pretreatment method for laser welding of aluminum alloy, laser cleaning pretreatment has been employed before the laser welding seam is fabricated with the ER 5356 filler wire on the surface of 7A52 aluminum alloy specimens. Morphological and compositional characteristics of the laser cleaning pretreated surface are analyzed to study the effect of laser cleaning pretreatment on laser welding formation quality. The results show that after laser cleaning, there is a wavy micro groove texture on the surface of the sample, which increases the surface roughness from 0.82 μm to 3.21 μm before pretreatment and its surface oxygen mass fraction is only 2.44%. Laser cleaning pretreatment method can obviously remove the original oxide films of the sample, reduce the formation tendency of process porosity and hydrogen porosity in the welding seam, significantly increase the absorptivity of the surface to the laser, improve the spreadability and wettability of the droplet on the surface, ultimately resulting in the enhancement of laser welding formation quality. Laser cleaning technique is proved to be an appropriate surface pretreatment method for laser welding on aluminum alloy.

关 键 词：激光焊接 激光清洗 7A52铝合金 氧化膜 焊接气孔 

分 类 号：TG456.7[金属学及工艺—焊接]