脉冲激光驱动的GMAW短路过渡行为控制

Pulsed laser controlled short-circuiting metal transfer in GMAW

关键词:  短路过渡  脉冲激光驱动  受迫短路  蒸发反力

Key words:  short-circuiting transfer  pulsed laser irradiation  laser recoil force  forced neckin

摘要:

试验研究了单侧脉冲激光照射熔滴控制短路过渡的行为.高能量密度的瞬时脉冲激光作用在熔滴上，产生的局部强烈的蒸发反力驱动熔滴受迫短路，形成液桥，完成收缩、破断，促进熔滴脱离焊丝.在无电弧条件下观察单侧脉冲激光驱动熔滴过渡的基础上，进一步分析了小电流下单侧脉冲激光驱动短路过渡的效果.结果表明，在焊接过程中施加一定能量密度和频率的脉冲激光对短路过渡行为有明显的改善作用，并能通过脉冲激光功率控制熔滴的尺寸，调节脉冲激光频率控制熔滴过渡频率，实现一脉一滴的过渡形式，提高焊接过程的稳定性.

Abstract:

The behavior of short-circuiting transfer controlled by single pulsed laser irradiation is studied. The high energy density of the instantaneous laser pulse acts on the droplet. The resulting local strong laser recoil force stretches the droplet toward the weld pool with slight radical deflection due to the use of single side laser. Consequently, the droplet is forced to short-circuit with the weld pool. And the liquid bridge of molten metal is thus formed. Since the laser irradiation still exists, the liquid bridge is continuously forced necked till the droplet is detached from the wire tip. Based on the observation of single pulse laser driven droplet transfer in the absence of arc, the short-circuiting transfer of pulsed-laser enhanced small-current GMAW is further analyzed. The results show that application of laser pulse with a certain peak power and pulse frequency has obvious effect on the short-circuiting droplet transfer behavior. The drop size can be controlled by adjusting the laser pulse parameters. One droplet per laser pulse short-circuiting transfer is obtained and the welding process stability is improved.