Dual-beam laser welding has been used to weld thick-section metals and for increasing keyhole stability leading to a better weld quality. So far, the development of dual-beam laser welding technologies has been in the experimental stage.
The objective of this paper is to develop mathematical models and the associated numerical techniques to calculate the transient heat transfer and fluid flow in the weld pool and to study weld pool dynamics during the dual-beam laser welding process. The simulation was conducted for a three-dimensional stationary dual-beam laser welding. The predicted changes of weld pool shape from an oval-like shape with a long-axis connecting the two lasers to another oval-like shape with a short-axis connecting the two lasers are similar to those observed from experiments. This interesting dynamical shape of the weld pool can be well explained by the predicted fluid flow field. Parametric studies were also conducted to investigate the effect of beam distance between the two lasers on the dynamical shape of the weld pool. Computer animations showing the transient fluid flow and weld pool dynamics will be presented.