Computational Modeling of Laser Additive Manufacturing Processes

The overall goal of the proposed research is to develop a comprehensive, efficient, and well-validated model for the prediction of the shape and thermal history of components manufactured using Laser Additive Manufacturing (LAM) processes. The proposed model will use a combined Eulerian-Lagrangian treatment for analyzing the three-dimensional gas-particle flow. Analysis of radiative heat exchange will account for specular radiation and scattering by powder particles. The temperature field in the deposition region will be determined by solving the energy conservation equation that accounts for phase change and free surface effects. Calculated thermal history will enable prediction of microstructure and residual stresses. Emphasis is placed on computational efficiency. Thus, radiative heat transfer will be calculated in the same grid used for gas-particle analysis. The Volume-of-Fluid technique will be used to predict shape evolution. A two-domain approach involving local mesh refinement and multigrid solution will be used for efficient analysis of the thermal interaction between small-scale deposition and large-scale bulk regions. The model will be validated with reference to available measurements on practical LAM units. A pilot commercialization effort will be undertaken in the later stages of the Phase II project with companies involved in the development and use of the LAM process.