Finite Element Models for Electron Beam Freeform Fabrication Process

This Small Business Innovation Research Phase II proposal offers to develop a comprehensive computer simulation methodology based on the finite element method for the simulation of the electron beam freeform fabrication process. It will utilize the successful accomplishments of Phase I project. The following major tasks are proposed for Phase II; (1) a user subroutine to model Gaussian distribution of the heat input, (3) a new highly sophisticated thermal model of material deposition, (4) a user subroutine for the prediction of microstructure with graphical representation of the output, (5) study of convection in the melt pool to determine its shape, (6) fabrication of three different types of samples and measurements of microstructure, residual stresses and distortions, and (7) computer simulation of the samples using all models developed under the program for their verification. A thermo-mechanical code ABAQUS will be the primary simulation tool. A computational fluid dynamics code, FLUENT, will be used for the study of the melt pool shape. These models will be applicable to ground-based as well as space-based EB systems. They will also be applicable to laser, TIG and other deposition processes. A strategy for the commercialization of the methodology and products is discussed.