Numerical Simulation of Asymmetrical Fluid Flow and Solidification During the Electron Beam Cold Hearth Re-melting (EBCHR) Process of Titanium Alloy TA10

Fluid flow in the solidifying pool plays an important role for the casting quality in electron beam cold hearth re-melting (EBCHR or EB Re-melting) process. A three-dimensional unsteady state model was built to describe the fluid flow and the sump evolution during the EBCHR process of titanium slab casting. The Mixed Lagrange and Euler (MiLE) approach was employed to investigate the unsteady state casting process. A set of asymmetrical EB power input was tested in the model to demonstrate the characteristic of the fluid flow, temperature distribution and sump profile. The results show that the asymmetrical sump is induced by the coupling of fluid flow and heat transfer within the asymmetrical mold. Part of the inlet fluid infiltrates the solidifying shell, and part of the inlet fluid rebounds to the melt surface. The infiltration of downward inlet flow reduces the solidifying shell, while the rebound of upward inlet flow enforces the heat absorption along the melt surface. The sump asymmetry can be adjusted with optimization of the EB power density. Copyright © 2020, Northwest Institute for Nonferrous Metal Research. Published by Science Press. All rights reserved.