Kao, A. ORCID: https://orcid.org/0000-0002-6430-2134, Gao, J. and Pericleous, K. ORCID: https://orcid.org/0000-0002-7426-9999 (2018) Thermoelectric Magnetohydrodynamic effects on the crystal growth rate of undercooled Ni dendrites. Philosophical Transactions of The Royal Society A: Mathematical, Physical and Engineering Sciences, 376 (2113). ISSN 364-503X (Print), 1471-2962 (Online) (doi:10.1098/rsta.2017.0206)

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Abstract

In the undercooled solidification of pure metals, the dendrite tip velocity has been shown experimentally to have a strong dependence on the intensity of an external magnetic field, exhibiting several maxima and minima. In the experiments conducted in China, the undercooled solidification dynamics of pure Ni was studied using the glass fluxing method. Visual recordings of the progress of solidification are compared at different static fields up to 6 T. The introduction of microscopic convective transport through thermoelectric magnetohydrodynamics is a promising explanation for the observed changes of tip velocities. To address this problem, a purpose-built numerical code was used to solve the coupled equations representing the magnetohydrodynamic, thermal and solidification mechanisms. The underlying phenomena can be attributed to two competing flow fields, which were generated by orthogonal components of the magnetic field, parallel and transverse to the direction of growth. Their effects are either intensified or damped out with increasing magnetic field intensity, leading to the observed behaviour of the tip velocity. The results obtained reflect well the experimental findings.

This article is part of the theme issue ‘From atomistic interfaces to dendritic patterns’.

Item Type:	Article
Additional Information:	© 2018 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.
Uncontrolled Keywords:	Undercooled growth, magnetic field, thermoelectric magnetohydrodynamics, numerical modelling
Subjects:	Q Science > QA Mathematics > QA75 Electronic computers. Computer science
Faculty / School / Research Centre / Research Group:	Faculty of Engineering & Science > Centre for Numerical Modelling & Process Analysis (CNMPA) Faculty of Engineering & Science > Centre for Numerical Modelling & Process Analysis (CNMPA) > Computational Science & Engineering Group (CSEG) Faculty of Engineering & Science > School of Computing & Mathematical Sciences (CMS) Faculty of Engineering & Science
Last Modified:	04 Mar 2022 13:07
URI:	http://gala.gre.ac.uk/id/eprint/18524

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