Regensburg 2013 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 22: Computational Materials Modelling - Phase Stability II

MM 22.3: Talk

Tuesday, March 12, 2013, 12:15–12:30, H24

A cluster-expansion Hamiltonian for the modeling of phase stabilities in the Ni-rich Ni-Al alloy — •Sascha B. Maisel, Michaela Höfler, and Stefan Müller — Institute of Advanced Ceramics, Hamburg University of Technology, Denickstrasse 15, Building K, 21073 Hamburg, Germany

Binary NiAl forms a well known stoichiometric phase called the γ’-Phase at 25 at. % Al. This phases shows a pronounced L1₂ ordering tendency and its precipitates are popular hardeners in many advanced alloys. Effective cluster-expansion interactions for the binary NiAl system between 0 and 25 at. % Al are needed as part of a larger project, which ultimately aims to supply model-Hamiltonians for multicomponent Ni-based super alloys. We have parametrized such an effective Hamiltionian for the Ni-rich Ni-Al alloy and present it in this talk, along with benchmarks of its efficiency and its accuracy in predicting formation enthalpies and phase boundaries when compared to both DFT input and experiments.