A Multiphysics numerical model for the laser metal deposition additive manufacturing process: Simplified approach & experimental validation

  • DALI, Ghassen (UTC - Roberval)

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Additive manufacturing is attracting wide interest within the scientific community and several research works are reported on the many variants of the process. Among these variants laser metal deposition (LMD) falls into the category so-called direct energy deposition (DED) process in which metal powder is blown into a laser generated melt pool. The laser beam is used to generate the melt pool and to heat the powder before it reaches the surface of the substrate. The melt pool then solidifies into a layer to build the part. In this work, we propose a finite element (FE) analysis workflow to simulate laser metal deposition (LMD) additive manufacturing at a mesoscopic scale (i.e. layer thickness scale). The developed model is used to predict thermal conditions during manufacturing, as well as the complex relations between the material deposition and the operating parameters. This predictive model takes into account fluid flow and heat transfer in all domains (gas, substrate and melt pool). This model, developed using the COMSOL Multiphysics software, simulates the track growth using droplet generation when the powder stream is intercepted by le laser beam. The material addition, the interface tracking and the strong topological changes are handled with the help of the level set technique. The predictions from the developed model are compared with experimental results for validation purpose. The comparisons include a crosschecking of the predicted melt pool dimensions and track geometry against experimental data from macrographs and high-speed videos.