Yuan, L., Lee, Peter D., Djambazov, Georgi ORCID: https://orcid.org/0000-0001-8812-1269 and Pericleous, Koulis A. ORCID: https://orcid.org/0000-0002-7426-9999 (2009) Multiscale modeling of the onset of freckle formation during vacuum arc remelting. In: Lee, Peter D., Mitchell, Alec and Williamson, Rod, (eds.) International Symposium on Liquid Metal Processing and Casting - LMPC 2009. The Minerals, Metals & Materials Society, Warrendale, Pennsylvania, USA, pp. 39-46. ISBN 978-0-87339-743-8

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Abstract

A multiscale model for the Vacuum Arc Remelting process (VAR) was developed to simulate dendritic microstructures during solidification and investigate the onset of freckle formation. On the macroscale, a 3D multi-physics model of VAR was used to study complex physical phenomena, including liquid metal flow with turbulence, heat transfer, and magnetohydrodynamics. The results showed that unsteady fluid flow in the liquid pool caused significant thermal perturbation at the solidification front. These results were coupled into a micromodel to simulate dendritic growth controlled by solute diffusion, including local remelting. The changes in Rayleigh number as the microstructure remelts was quantified to provide an indicator of when fluid flow channels (i.e. freckles) will initiate in the mushy zone. By examining the simulated microstructures, it was found that the Rayleigh number increased more than 300 times during remelting, which suggests that thermal perturbation could be responsible for the onset of freckle formation.

Item Type:	Book Section
Additional Information:	This paper forms part of the Proceedings from the International Symposium on Liquid Metal Processing and Casting - LMPC 2009, held 20-23 September 2009, in Santa Fe, New Mexico, USA. The Proceedings are available for purchase on CD ROM format.
Uncontrolled Keywords:	multiscale modeling, freckle formation, remelting, Rayleigh number
Subjects:	T Technology > TS Manufactures T Technology > TN Mining engineering. Metallurgy Q Science > QA Mathematics
Pre-2014 Departments:	School of Computing & Mathematical Sciences School of Computing & Mathematical Sciences > Centre for Numerical Modelling & Process Analysis School of Computing & Mathematical Sciences > Centre for Numerical Modelling & Process Analysis > Computational Science & Engineering Group School of Computing & Mathematical Sciences > Department of Computer Systems Technology School of Computing & Mathematical Sciences > Department of Mathematical Sciences
Related URLs:	Publisher Organisation
Last Modified:	05 Mar 2019 11:38
URI:	http://gala.gre.ac.uk/id/eprint/1486

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