Dresden 2011 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 12: Postersitzung I
MM 12.18: Poster
Montag, 14. März 2011, 17:30–19:00, P5
Cluster Expansion study of FexNiyAl1−x−y alloys — •Georg Kastlunger, David Reith, Markus Stöhr, and Raimund Podloucky — Faculty of Chemistry, Univ. Vienna
Cluster expansion (CE) is the state of the art tool to derive concentration dependent properties of alloys with the precision of density functional theory calculations. In this work we apply CE for a ternary system to study thermodynamical phase stabilities for FexNiyAl1−x−y alloys crystallizing in bcc-based structures. For studying Ni-Al precipitations in Fe (steel) the concentration range was defined correspondingly. On the basis of DFT total energy calculations for about 350 compounds we derived the effective cluster interaction energies (ECI) by a genetic algorithm employing the UNCLE (UNiversal CLuster Expansion) code[1]. After an extensive ground state search the stable phases and their convex free energy hull were identified. For constructing the phase diagram at finite temperatures the converged ECIs were used in both, canonical and grand-canonical Monte-Carlo simulations.
[1] D. Lerch, O. Wieckhorst, G.L.W. Hart, R.W. Forcade, and S. Müller, Modelling Simul. Mater. Sci. Eng. 17, 055003 (2009).