Numerical simulation and experiments on the behavior and mechanism of laser-assisted droplet transfer

With the advantages of high energy density, high flexibility, and good material adaptability, lasers have been used to transfer droplets to the molten pool in the welding and additive manufacturing fields. In this study, a laser-assisted droplet transfer process was simulated using COMSOL Multiphysics software. Based on the angular impulse physical model, the effects of incidence position and laser power on the shape, spatter, and detachment direction of a droplet were predicted and analyzed. The droplet detached from the wire tip when the laser beam was irradiated at the solid-liquid interface under a laser power of 1200 W and a pulse width of 10 ms. When the power was 1400 W, the droplet exhibited a regular shape and little spatter. The droplet detached along the laser incidence direction, in accordance with the desired direction of laser-assisted droplet transfer.