脉冲激光与电弧布置方式对铝合金焊接熔滴过渡与焊缝形貌的影响

以2219铝合金为基板,研究了不同脉冲激光-电弧布置方式下的熔滴过渡与焊缝形貌特征,分析了熔深增加的机理. 结果表明,当脉冲激光照射母材时,脉冲激光主要提供对母材的热输入,母材温度的增加有助于促进熔滴铺展,稳定熔滴过渡过程;当脉冲激光照射熔滴缩颈时,主要提供对熔滴的力输入,蒸发反力的作用下形成"一脉一滴",显著提高熔滴过渡频率与熔滴飞行速度,增加了熔滴对熔池的冲击力,熔深增加;当脉冲激光交替的照射熔池和熔滴时,一方面能够对母材进行加热,有助于熔滴的铺展,另一方面能够提高熔滴过渡频率,提高焊缝的均匀性.

Effect of pulse laser-arc arrangement on metal transfer and bead formation characteristics of aluminum alloy welding

2219 aluminium alloy with 5 mm thickness was used as the experimental material, the metal transfer and bead formation characteristics of aluminum alloy welding under different pulse laser-arc arrangement (i.e. different laser incident points) were studied, and the mechanism for the increase of weld penetration was analyzed. The results show that when the pulse laser irradiates the base material, it mainly provides heat input to the base metal, and the temperature increase of the base material helps to promote the droplet spread and stabilize the metal transfer process; when the pulse laser illuminates the solid-liquid interface of the droplet, it primarily provides a recoil force to the droplet. A stable "one pulse per droplet" transfer is obtained, which significantly increases metal transfer frequency and the droplet flight speed. The welding penetration is enhanced by the increase of droplet impact force on the molten pool. When the pulsed laser alternately illuminated the molten pool and the droplet, on the one hand, the base material can be heated to facilitate the spreading of the droplet, and on the other hand, the metal transfer frequency and the uniformity of the bead formation can be improved.