Gilles Demange, Mykola Lavrskyi, Renaud Patte
GPM, UMR CNRS, University of Rouen, France
Multiscale modelling of precipitation kinetics in the presence of elastic effects in alloys
The mechanical properties of metallic materials are determined by their microstructure, and in particular, the different morphologies of precipitates lead to distinct strengthening effects. This why modeling of precipitation kinetics has always been an area of intense activity in physical metallurgy. In mostly of cases this kinetics is governed not only by the chemical driving force but also by the elastic interactions arising from a difference of lattice spacing between matrix phase and coherent precipitates. In this work the effect of coherent elastic strain on the coarsening kinetics and shape instabilities of a single precipitate in Ni-based, Cu-based and Fe-based alloys in an elastically anisotropic cubic system is examined using the phase field modeling, atomic density function theory and recently proposed, the quasiparticle approach. These three approaches have been applied in an effort to investigate the formation of concave interfaces of a coherent Fe-rich particle in Cu-Fe alloys, the coarsening kinetics in Ni-Al alloys and the decomposition kinetics in Fe-C system at different length scales. It is shown that the interplay between elastic and chemical driving forces play a key role in understanding the microstructural evolution in these systems.