Finite Element Models for Electron Beam Freeform Fabrication Process

This Small Business Innovation Research proposal offers to develop the most accurate, comprehensive and efficient finite element models to date for simulation of the material deposition processes; especially the electron beam freeform fabrication process. Phase I will deal with the basic thermal and mechanical (stress and distortion) models. A new scheme to model material deposition will be attempted; its feasibility will be tested on multi-pass deposits. A commercial finite element analysis code, ABAQUS, will be used to which a new capability for prediction of morphology will be added. During Phase II, several other key modeling issues such as the prediction of grain size, study of the effect of convection in the melt pool, parametric study, experimental validation, simulation of a demonstration part, and on-line process control will be addressed. These models will be applicable to ground-based as well as space-based systems. They will assist in understanding the effects of the various process parameters (e.g., power, feed rate, traverse speed and gravity) on variables defining the product quality; e.g., interlayer fusion, morphology, grain size, stresses and distortion. The models will also be applicable to laser, TIG and other metal deposition processes.