Decoupling control of metal transfer in GMAW by pulsed laser irradiation

Current-independent metal transfer, i.e., to detach droplets in small drop globular or even drop spray mode at any reasonable low current, will fundamentally improve the process stability and weld quality of GMAW process. Toward this ultimate goal, an innovative method that uses a pulsed fiber laser to irradiate the droplet and then detach the droplet is proposed. The laser induced vaporization is first experimentally studied. The laser pulse controlled metal transfer are then observed and studied. The results show that the laser method can fully decouple the droplet detachment from the welding current. The metal transfer mode is ODPP mode.