Modeling Ordered Phases using Compound Energy Formalism

20 May 2010 (Thu), 13:30 - 15:00

8F large seminar room, Central Bldg., Sengen site

Professor Bo Sundman

INSTN, CEA-Saclay, France

Modeling Ordered Phases using Compound Energy Formalism

The thermodynamic modeling of chemical ordering in multicomponent alloys will be presented. First ordering in binary systems, like in FCC phases as in Al-Ni and Au-Cu and in BCC phases as in Al-Fe and Fe-Ti will be explained.

The modeling of ordering is very dependent on the use of first principle calculations to obtain enthalpies of formation for meta-stable ordered states. Then extrapolation of the ordering into ternary and higher order systems will be discussed. The approximation of the short range ordering contribution to the Gibbs energy in the Compound Energy Formalism will be explained. The modeling of ordered phases that never disorder, like s and m, will also be discussed.

References:

B Sundman, S G Fries and W A Oates, A Thermodynamic Assessment of the Au-Cu system, Calphad, 22 (1998) 335-354.

T Abe and B Sundman, A description of the effect of short range ordering in the compound energy formalism, Calphad 27 (2003) 403-408

N Dupin, S G Fries, J M Joubert, B Sundman, M H F Sluiter, Y Kawazoe and A Pasturel, Using first-principles results to calculate finite-temperature thermodynamic properties of the Nb-Ni m phase in the Bragg-Williams approximation, Phil Mag 86 (2006) 1631-1641

H.L. Lukas, S.G. Fries and B. Sundman, Computational Thermodynamics, Cambridge University Press, 2007

B Sundman, N Dupin, U Kattner, I Ohnuma and S G Fries, An assessment of the entire Al-Fe system with D03 ordering, Acta Materialia 57 (2009) 2896-2908.

Dr. Taichi Abe(阿部太一)