Heat transfer and flow of molten pool in single track multi-layer aluminum alloy laser wire additive manufacturing

Abstract

In the process of single track multi-layer aluminum alloy laser wire additive manufacturing, there is a lack of in-depth understanding of the heat transfer and dynamics within the melt pool, and it is difficult to characterize the flow behavior inside the melt pool. This paper introduces the numerical simulation of single-track multi-layer aluminum alloy laser wire additive manufacturing. Through numerical simulation methods, the continuous feeding of the wire is realized in the form of mass source terms. The results show that as the specific energy K increases, the length and depth of the molten pool gradually increase, the Marangoni force and thermal buoyancy are enhanced, and the flow speed of the molten pool gradually increases. As the number of layers increases, the heat accumulation between layers increases linearly. Finally, the laser attenuation strategy was adopted, and the laser power of each layer was decreased by 100 W. The flow mode in the molten pool transformed from non-rotational to rotational, and the flow velocity of the molten pool was reduced to 0.187 m/s, and the sedimentary layer with excellent geometric morphology was obtained.