Analysis of programmable metal transfer transition in GMAW driven by asymmetric arrangement of bilateral laser pulses

The core of programmable droplet transition is to realize the controlled directional deflection transition of the droplets in a certain area, and to regulate the droplet landing point by matching laser pulse program. On the basis of the symmetric arrangement of laser pulses, a programmable transition control strategy is proposed in the paper for the programmable transition of molten drops driven by the asymmetric arrangement of bilateral lasers. The effects of the pulsed laser process parameters on the transition behavior and deflection angle of the droplets under the asymmetric arrangement are investigated. The results show that, unlike the symmetric laser arrangement, one side of the asymmetric laser arrangement irradiates the solid-liquid interface and plays a cutting role at that point, while the other side of the laser irradiates the droplet body and mainly produces an impact effect on the droplet. The deflection of the droplet is mainly determined by the impact of the laser on the droplet on the right side, and the maximum deflection range of the droplet increases to 55 °. A calculation model for the impact force of deflected droplets on the molten pool was established based on the force situation of the droplets. By using high-speed cameras to capture the transition process of the droplets, the impact force of the droplets on the molten pool can be calculated.