Numerical simulation of heat transfer and fluid flow during laser metal wire deposition

Abstract

The object of the research project on which the following article reports, is to develop a numerical simulation model which predicts the geometry of a component manufactured by robotized laser metal wire deposition (RLMwD). These simulations are meant to assist in process planning and optimization. The work is carried out under the assumption that the flow of liquid metal exercises a significant influence on the shape of each bead, and thus also on the entire deposit.Here we present a 3D time dynamic finite element model of the RLMwD process. Previous work emphasized the simulation of heat transfer and liquid metal flow under the assumption that the deposition of single beads could be analysed considering a transversal slice of the substrate and deposited mass. In order to treat complex deposition patterns, we have at the present stage adopted this model to the simulation of heat transfer in three spatial dimensions, while taking into account the mass and heat transfer implied by the addition of filler wire. Temperature data collected from experiments performed on Ti-6Al-4V was used for calibrating the model coefficients which define the heat input from the irradiating laser beam and the heat loss to the fixture and surrounding gas.The object of the research project on which the following article reports, is to develop a numerical simulation model which predicts the geometry of a component manufactured by robotized laser metal wire deposition (RLMwD). These simulations are meant to assist in process planning and optimization. The work is carried out under the assumption that the flow of liquid metal exercises a significant influence on the shape of each bead, and thus also on the entire deposit.Here we present a 3D time dynamic finite element model of the RLMwD process. Previous work emphasized the simulation of heat transfer and liquid metal flow under the assumption that the deposition of single beads could be analysed considering a transversal slice of the substrate and deposited mass. In order to treat complex deposition patterns, we have at the present stage adopted this model to the simulation of heat transfer in three spatial dimensions, while taking into account the mass and heat transfer implied by the addition of filler wi...