Using methods of statistical kinetic theory parametrized with first-principles interatomic interactions that include chemical and strain contributions, we investigated the kinetics of decomposition and microstructure formation in Al-Cu alloys as a function of temperature and alloy concentration. We show that the decomposition of the solid solution forming platelets of copper, known as Guinier-Preston (GP) zones, includes several stages and that the transition from GP1 to GP2 zones is determined mainly by kinetic factors. With increasing temperature, the model predicts a gradual transition from platelet-like precipitates to equiaxial ones and at intermediate temperatures both precipitate morphologies may coexist.
@article{arxiv.1711.04984,
title = {Solid solution decomposition and Guinier-Preston zone formation in Al-Cu alloys: A kinetic theory with anisotropic interactions},
author = {A. Yu. Stroev and O. I. Gorbatov and Yu. N. Gornostyrev and P. A. Korzhavyi},
journal= {arXiv preprint arXiv:1711.04984},
year = {2018}
}