Computational Modeling of Cold-Hearth Melting Processes

The overall objective of the proposed research is to develop a comprehensive, efficient, and well-validated computational model for the prediction of the process performance and quality of the titanium alloys produced using the Electron Beam Melting (EBM) and Plasma Arc Melting (PAM) processes. The computational model will analyze all the underlying physical phenomena in cold hearth melting namely, flow, heat transfer, phase change, electromagnetics, inclusion transport, alloy element volatilization (EBM), and helium entrapment (PAM). The model will also consider the transient effects caused by the motion of the heat source and periodic freezing and melting of the conduits connecting successive hearths. The computational solution will utilize many novel features for obtaining computational efficiency. These include an efficient treatment of the coupling among the hearths, a multigrid solution technique, and use of a Lagrangian technique for the prediction of the motion and dissolution of the inclusions. The model will be validated with reference to available measurements on practical EBM and PAM furnaces. The Phase I effort will demonstrate the feasibility of developing a computational model for the EBM and PAM processes by focusing on the analysis of flow, heat transfer, alloy vaporization, and helium entrapment phenomena in a single hearth.