Paper 9.1

First-principles calculation of phase equilibria and extension to hybridized calculation with Phase Field Method

Mohri T.¹, Chen Y.² and Ohno M.¹

¹Division of Materials Science and Engineering, Graduate School of Engineering, Hokkaido University, Sapporo, Japan

²Department of Quantum Engineering and System Science, School of Engineering, The University of Tokyo

First principles investigation of phase equilibria for Fe-Ni, -Pd and -Pt systems have been performed based on FLAPW electronic structure calculations combined with Cluster Variation Method via Cluster Expansion Method. The main focus is placed on the L10-disorder phase equilibria. The obtained transition temperatures are in good agreements with experimental results. The effective interaction energies derived by Cluster Expansion Method are critically examined.

In order to gain insight of ordering and disordering phenomena, Phase Field calculations are attempted at a fixed composition of 50at%. Three characteristic time scales in the formation of Anti-Phase Domains are separated. One is atomistic, another is wetting and the last one is the coarsening including coalescence events. The extension of the first-principles investigation to microstructural evolution process is discussed.