Multi-scale modelling of discontinuous precipitation in Ni-Cr alloys M/F

Job Description

Thesis Subject

Discontinuous precipitation (DP) is a solid-state phase transformation observed in many metallic alloys, such as Al, Mg, Ni-based alloys, and HEAs. During this complex process, a supersaturated parent phase decomposes at a moving grain boundary into a precipitate phase and a residual depleted phase, forming a lamellar structure. DP occurs in an evolving complex microstructure consisting of large grains with different
orientations. This microstructure evolution generally degrades the material's mechanical and chemical properties, leading to a loss of hardness and/or corrosion resistance.

The PhD is part of the broader ANR (French National Research Agency) project “ADISCO”, which aims to investigate the micromechanical and microstructural mechanisms governing DP in Ni-Cr alloys. Grain boundaries, which act as preferential pathways for rapid solute diffusion and as nucleation sites for new phases, must be fully considered in terms of both their topology (grain shapes and polycrystalline texture) and their anisotropic properties (energy, diffusivity, and mobility) to achieve a complete
description of DP. Phase-field modelling provides a general framework for predicting microstructural evolution in complex systems. In a novel approach, we employ a phase-field model capable of describing the evolution of grains while accounting for the different physical mechanisms involved in DP. The model will be parametrized
using data from atomistic simulations as well as experiments carried out by our research group. The primary goal of this project is to identify the key physical parameters that control the initiation and growth of DP colonies. These insights will be used to interpret experimental observations of DP in Ni-Cr alloys.

The PhD project will provide comprehensive training in modelling approaches (molecular statics, CALPHAD, and phase-field methods), with the possibility to gain experience in characterization techniques (SEM, TEM) depending on the candidate's interests and aptitudes.

Skills/Qualifications :
The applicant must hold a Degree in Solid State Physics or Materials Science, ideally with knowledge in:
- physical metallurgy, phase transformations, out of equilibrium thermodynamics, atomic diffusion),
- computational physics (ab initio, molecular statics, micromechanics),
- Interest in computer programming is also a plus (Fortran, Python).
The applicant must be fluent in English and/or French.

Your Work Environment

The Institute Jean Lamour (IJL) is a joint research unit of CNRS and Université de Lorraine.
Focused on materials and processes science and engineering, it covers: materials, metallurgy, plasmas, surfaces, nanomaterials and electronics.
By 2026, IJL has 258 permanent staff (33 researchers, 133 teacher-researchers, 92 IT-BIATSS) and 389 non-permanent staff (146 doctoral students, 43 post-doctoral students / contractual researchers and more than 200 trainees), from some seventy different nationalities.
Partnerships exist with 150 companies and our research groups collaborate with more than XX countries throughout the world.
Its exceptional instrumental platforms are spread over 4 sites ; the main one is located on Artem campus in Nancy.

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

The research professions