Precipitate growth in concentrated binary alloys: a comparison between kinetic Monte Carlo simulations, cluster dynamics and the classical theory

Abstract

The numerical modelling of concentrated alloy precipitation kinetics remains a challenge at all scales. At the microscopic scale, kinetic Monte Carlo (KMC) simulations can cope with nucleation and early growth whatever the solute concentration may be; it cannot, however, address coarsening. At the mesoscopic scale, the advantage of cluster dynamics (CD) is its ability to describe the whole kinetics of precipitation but lacks of reliability for nucleation in concentrated alloys. Finally, analytical models are preferred at the macroscopic scale for their simplicity, their flexibility and their ability to be incorporated within more general approaches, to predict mechanical properties, for instance. The present work aims at examining the ability of CD and classical analytical models to describe the growth of an isolated precipitate in a concentrated binary alloy, by comparison with KMC simulations taken as the reference.

Keywords:

• cluster dynamics
• precipitation
• free energy

Acknowledgements

The authors are grateful to Dr E Clouet for providing his KMC code developed in CEA Saclay. Prof P Guyot is also gratefully acknowledged for his helpful remarks about the manuscript.