Multiscale modeling of precipitation hardening: Application to the Fe-Cr alloys

Precipitation hardening is investigated using dislocation dynamics (DD) simulations. Unlike classical approaches, precipitates are represented by an interaction potential, completely determined from atomistic simulations (ASS), including size and temperature effects. The transition method is first validated by comparing DD and ASs of interactions with one precipitate using the same simulation conditions and, then, applied in massive DD simulations for the prediction of hardening as a function of precipitate size, density and shear resistance over a large range of temperatures. Results show that hardening is always proportional to the Orowan hardening with an interaction coefficient depending on the effective resistance of the precipitates. A simple theoretical model is found to describe appropriately the ensemble of the reported results. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.