Classical nucleation theory in ordering alloys precipitating with L12 structure

Emmanuel Clouet (1) , Maylise Nastar (1)

1 SRMP - Service de recherches de métallurgie physique

By means of low-temperature expansions (LTEs), the nucleation free energy and the precipitate interface free energy are expressed as functions of the solubility limit for alloys which lead to the precipitation of a stoichiometric L12 compound such as Al-Sc or Al-Zr alloys. Classical nucleation theory is then used to obtain a simple expression of the nucleation rate whose validity is demonstrated by a comparison with atomic simulations. LTEs also explain why simple mean-field approximation like the Bragg-Williams approximation fails to predict correct nucleation rates in such an ordering alloy.

Mots clés: aluminium alloys; scandium alloys; zirconium alloys; nucleation; precipitation; free energy; surface energy; stoichiometry

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Emmanuel Clouet, Maylise Nastar. Classical nucleation theory in ordering alloys precipitating with L12 structure. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2007, 75 (13), pp.132102. ⟨10.1103/PhysRevB.75.132102⟩. ⟨hal-00141829⟩