Mobility of dislocations decorated by carbon atoms in iron

6 months - This internship can be followed by a PhD thesis

CEA Saclay - 91190 Gif-sur-Yvette, France

Personnes à contacter par le candidat

Lisa VENTELON, lisa.ventelon@cea.fr

DATE DE DÉBUT SOUHAITÉ

01/03/2022

TÉLÉCHARGEZ L’OFFRE

Summary of the project

Metals and alloys with body centered cubic structure represent an important class of structural materials in industry, and in particular in the energy sector. The presence of interstitial impurities, such as carbon in iron, modifies the plastic behaviour of the material, notably by inducing the so-called dynamical strain ageing phenomenon, commonly observed in ferritic steels, which results from the interaction between dislocations and solute atoms. The goal of this project is to study the link between dislocation mobility and solute atom diffusion. To this end, numerical simulations will be used in order to improve our fundamental understanding of the effect of carbon on dislocation glide in iron. This requires a multi-scale coupling between ab initio electronic structure calculations and kinetic model of dislocation glide and solute diffusion, in order to describe the mechanisms underlying the mobility of dislocations and carbon. These simulations will make it possible to establish mobility laws for the dislocation in the presence of carbon. We will build on recent observations by in-situ straining experiments in a transmission electron microscope in Fe(C).