Computational Materials Science Group

Gyula Tóth¹, J.R. Morris², László Gránásy^3,4

¹Department of Mathematical Sciences, Loughborough University, Loughborough, Leicestershire, LE11 3TU, U.K.
²Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, USA
³Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, P.O. Box 49, Budapest H-1525, Hungary
⁴BCAST, Brunel University, Uxbridge, Middlesex, UB8 3PH, United Kingdom

We address crystal nucleation and fcc-bcc phase selection in alloys using a multiphase field model that relies on Ginzburg-Landau free energies of the liquid-fcc, liquid-bcc, and fcc-bcc subsystems, and determine the properties of the nuclei as a function of composition, temperature, and structure. With a realistic choice for the free energy of the fcc-bcc interface, the model predicts well the fcc-bcc phase-selection boundary in the Fe-Ni system.