Computational Modeling of Remelting Processes for Ingot Casting of High-Performance Alloys

The overall goal of the proposed research is to develop a comprehensive, efficient, and well validated model of various remelting processes used for the production of ingots of superalloys and titanium alloys. Phase I research has demonstrated thefeasibility and the validity of developing a unified computational model for efficient and accurate prediction of AC and DC electromagnetics, fluid flow, and heat transfer phenomena in ESR, VAR, and EB remelting processes under axisymmetric, steady stateconditions. Phase II research will involve extensions of the computational framework to enable a more comprehensive analysis of the physical phenomena. These include prediction of unsteady and three-dimensional effects, macrosegregation, microstructure,and inclusion transport. Emphasis is placed on achieving computational efficiency to facilitate effective use of the model. Thus, computational innovations include ballooning boundary conditions in electromagnetics analysis, expanding grid for treatingingot growth, two-domain method for predicting macrosegregation, and multigrid method for efficient solution. Experimental measurements on research and production units will be used for a detailed validation of the enhanced model. The model will then beapplied for the design and optimization of practical remelting processes by our industrial partners. This will be followed by a full-scale commercialization in Phase III effort.