Coupling analysis of molten pool during fused coating process with arc preheating

Abstract

Fused coating process with arc preheating is a new developing additive manufacturing technology. In addition to the high efficiency and low cost, it solves the spread difficulty of lightweight alloys such as aluminum alloy. In this paper, separating and coupling effect of driving forces exerted on weld molten pool caused by the arc is analyzed. Evolution of temperature field and flow field is described in detail. It is found that the magnitude order of the force's influence is surface tension>arc pressure> Lorenz force>drag force>buoyancy force. With the increase of the molten pool depth, the influence of the Lorentz force gradually increases and exceeds the surface tension at the bottom of the molten pool. Heat and mass transfer between the molten pool and externally added liquid metal is also calculated. External liquid metal rapidly flows into the molten pool at the moment of contact under the influence of surface tension and molecular affinity. Weld pool size and single pass morphology are measured and compared with the numerical simulation results to verify the accuracy of the model, and it turned out that the dimensional errors are all less than 10%.