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

Evteev, Alexander V.; Levchenko, Elena V.; Momenzadeh, Leila; Sohn, Yongho; Belova, Irina V.; Murch, Graeme E.

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
Creator: Evteev, Alexander V.; Levchenko, Elena V.; Momenzadeh, Leila; Sohn, Yongho; Belova, Irina V.; Murch, Graeme E.
Relation: ARC
Relation: Philosophical Magazine Vol. 95, Issue 1, p. 90-111
Publisher Link: http://dx.doi.org/10.1080/14786435.2014.984006
Publisher: Taylor & Francis
Resource Type: journal article
Date: 2015
Description: 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 2000 K and less than 1% at 3000 and 4000 K. 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.
Subject: thermal transport; thermal conductivity; phonons; molecular dynamics; Green–Kubo formalism; liquid; Ni–Al system
Identifier: http://hdl.handle.net/1959.13/1333359
Identifier: uon:27066
Identifier: ISSN:1478-6435
Language: eng
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