Modeling of Direct Energy Deposition for Wire Laser Additive Manufacturing

This work discusses the relevance of direct energy deposition (DED) and its classifications. Different types of DED processes are discussed, including their main parameters and issues. Two experiments were carried out, named single bead and rectangular prism, for the purpose of this research. These were built with a hot wire and laser DED system, where experimental thermal data were obtained, later geometric information was obtained via a 3D scan. Limitations of the equipment used as well as observed defects in the material deposition are discussed based on the experimental data. FEA models were developed to duplicate the experiments, which included a detailed geometry of the single bead. Two modifications to the bead geometry are presented and evaluated, where it is was concluded that a semi-circular bead approximation provides better results than if a rectangular one is assumed. This led to the definition of a thermal and structural equivalent model of the single bead, which was the basis for the numerical work of the rectangular prism. The results obtained for the latter show good agreement with the thermal results, although differences in the structural results are perceptible.