Simulation of dendrite growth in the laser welding pool of aluminum alloy 2024 under transient conditions

A macroscopic heat transfer and fluid flow model is developed to calculate the temperature and velocity fields in the laser welding pool of aluminum alloy 2024. The equations of temperature gradient and solidification rate are developed to consider the transient conditions during the laser welding process. The dendrite growth and solute concentration along the fusion boundary are predicted via the phase-field model under the transient conditions. The comparison of the simulation results with the measurements is carried out. Fusion profiles obtained by using a rotary-Gauss body heat source model are consistent with measurements. The computed dendrite morphology and primary dendrite arm spacing give a good agreement with experimental findings.