Title

Molecular dynamics study of phonon-mediated thermal transport in a Ni50Al50 melt: case analysis of the influence of the process on the kinetics of solidification

Authors

Authors

A. V. Evteev; E. V. Levchenko; L. Momenzadeh; Y. Sohn; I. V. Belova;G. E. Murch

Comments

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Abbreviated Journal Title

Philos. Mag.

Keywords

Ni-Al system; molecular dynamics; liquid; phonons; thermal conductivity; Green-Kubo formalism; thermal transport; EMBEDDED-ATOM-METHOD; IRREVERSIBLE-PROCESSES; CRYSTAL-GROWTH; MECHANICAL-PROPERTIES; RECIPROCAL RELATIONS; INTERMETALLIC PHASE; INTERFACE KINETICS; LIQUID-MIXTURES; SIMULATION; ALLOY; Materials Science, Multidisciplinary; Mechanics; Metallurgy &; Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter

Abstract

The phonon-mediated contribution to the thermal transport properties of liquid NiAl alloy is investigated in detail over a wide temperature range. The calculations are performed in the framework of equilibrium molecular dynamics making use of the Green-Kubo formalism and one of the most reliable embedded-atom method potentials for the intermetallic alloy. The phonon-mediated contribution to the thermal conductivity of the liquid alloy is calculated at equilibrium as well as for the steady state. The relative magnitude of the thermal conductivity decrease induced by the transition to the steady state is estimated to be less than 2% below 2000K and less than 1% at 3000 and 4000K. It is also found that the phonon-mediated contribution to the thermal conductivity of the liquid alloy can be accurately estimated (well within 1%) on the basis of an approximation which invokes the straightforwardly accessible microscopic expression for the total heat flux without demanding calculations of the partial enthalpies needed for the precise evolution of the reduced heat flux (pure heat conduction). On the basis of these calculations, the correspondence between the experimentally observed and modelled kinetics of solidification due to a difference in thermal conductivity is discussed.

Journal Title

Philosophical Magazine

Volume

95

Issue/Number

1

Publication Date

1-1-2015

Document Type

Article

Language

English

First Page

90

Last Page

111

WOS Identifier

WOS:000346846700007

ISSN

1478-6435

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