Université de Lorraine

PhD thesis: Motion and packing of dendrites during solidification – modeling and scale bridging

2024-05-31 (Europe/Paris)
Save job

Offer Description


Metallic materials are composed of crystal microstructures and their mechanical properties depend on the size, morphology, and chemical composition of these microstructures. In manufacturing of virtually all metal products, solidification processes, such as casting, welding, or additive manufacturing, are a decisive step for the formation of the microstructure. Understanding the link between process parameters and the microstructure of the product is particularly important for the improvement of properties of high- performance components with high added value, e.g., the impact toughness of steel nuclear reactor pressure vessels or the fatigue strength of turbine blades in an aircraft engine.

During the solidification of a metal alloy, the solid crystal structure often forms in the shape of dendritic grains. The dendrites, a few millimeters in size, first grow freely in the liquid and can move during their growth. They are carried by the flow and are spread across the whole solidifying piece, which can be several meters in size. They sediment, pack, and continue to grow until complete solidification. The structure of the solidified piece depends strongly on these transport phenomena.

Our work on the dynamics of motion of dendritic grains has shown that the transition between the zone of free-floating grains and the packed layer of stationary grains occurs across a narrow zone, with the thickness of about 5 times the grain size. In this packing zone, the distance between the grains decreases rater abruptly and the coupling between the flow of the liquid, the motion of the grains and their growth leads to high variations of chemical composition and temperature. Today, a theory to describe the packing zone does not exist. The phenomena in this zone are one of the key factors for the formation of the nonuniform structure and chemical composition in castings.

Objectives and Methods

The objective of the PhD thesis is to answer the following questions:

  • What are the principal phenomena that control the formation of the structure in the grain packing zone?
  • How can we describe the packing zone at a macroscopic scale of the solidifying part in order to incorporate the description into a model for the simulation of the industrial process?

Experimental characterization of the phenomena in the packing zone is extremely difficult. However, recently developed mesoscopic models of solidification can provide detailed quantitative information on the evolution of the shape and size of the grains, concentration and thermal fields, etc. They can simulate ensembles of up to a hundred grains; it is therefore possible to carry out numerical experiments and characterize all these aspects.

The Grain Envelope Model (GEM) will be employed to investigate the growth and motion of the grains, as well as the relevant couplings in the packing zone. The GEM describes the growth of individual grains, coupled with a CFD finite-volume modeling of flow, diffusion and heat transfer and with a DEM (Discrete Element Method) model of contact between grains. The code is developed on the OpenFOAM platform. The project will consist of the following steps:

  1. An extension of the GEM will be developed to incorporate the phenomena in the packing zone into the model.
  2. Simulations of solidification in the packing zone will be performed for prototype configurations, relevant for the conditions encountered in metallurgical processes.
  3. The simulations will be upscaled to formulate constitutive laws that describe the solidification in the packing zone in macroscopic process models.


Research Field Engineering » Mechanical engineering

Education Level Master Degree or equivalent

Research Field Engineering » Aerospace engineering

Education Level Master Degree or equivalent

Research Field Physics

Education Level Master Degree or equivalent

Research Field Engineering » Materials engineering

Education Level Master Degree or equivalent

Research Field Engineering » Process engineering

Education Level Master Degree or equivalent


  • Good notions of heat & mass transfer, fluid dynamics, numerical methods.
  • Experience in numerical modeling (finite volume method appreciated).
  • Proficiency in computer programming (C++, Python, OpenFOAM).
  • Proficiency in technical report writing and presentation.
  • Sense of initiative, problem-solving and teamwork skills.
  • Fluent in English, some knowledge of French beneficial.

Languages ENGLISH

Level Excellent

Languages FRENCH

Level Basic

Research Field Engineering » Materials engineering

Years of Research Experience None

Additional Information

Selection process

The position is open until filled. Eligible applicants will be interviewed by an ad hoc committee after receipt of the application.

Additional comments

Institut Jean Lamour (IJL) falls under a Zone à régime restrictif (ZRR). The selected applicants will be subject to a Security Clearance check, required for employment at IJL.

Website for additional job details


Work Location(s)

Number of offers available 1

Company/Institute Institut Jean Lamour

Country France

City Nancy

Postal Code 54000

Street 2 allée André Guinier

Where to apply

E-mail miha.zaloznik@univ-lorraine.fr


City Nancy

Website http://ijl.univ-lorraine.fr

Street Campus Artem, 2 allée André Guinier

Postal Code F-54000



Apply now

Fill out the form below to apply for this position.
Upload your CV and attachments*

*By applying for a job listed on Academic Positions you agree to our terms and conditions and privacy policy.

By submitting this application, you consent to us retaining your personal data for service-related purposes. We value your privacy and will handle your information securely. Should you wish for your data to be removed, please contact us directly.

Job details

PhD thesis: Motion and packing of dendrites during solidification – modeling and scale bridging
34 Cours Léopold Nancy, France
Application deadline
2024-05-31 23:59 (Europe/Paris)
2024-05-31 23:59 (CET)
Job type
Save job

More jobs from this employer

About the employer

Université de Lorraine promotes innovation through the dialogue of knowledge, taking advantage of the variety and strength of its scientific fields...

Visit the employer page

This might interest you

Control Systems: The Key to Our Automated Future? Max Planck Institute for Software Systems (MPI-SWS) 5 min read
Lighting the Way in the Search for Distant Exoplanets SRON - Netherlands Institute for Space Research 4 min read
3D Printing for Better Healthcare Medical University of Vienna 4 min read
More stories