Main objective and key accountabilities

Contribute do the development of a comprehensive understanding of the nucleation, growth, and subsequent evolution of Fe-containing intermetallic (Fe-IM) phases in aluminium alloys in order to refine their morphology and distribution, ultimately enabling the design of next-generation recycling-friendly aluminium alloys with increased recycled content and improved performance.

Building upon an ongoing research effort initiated in 2023 through a previous internship and continued within a collaborative PhD project between Constellium C-TEC and Sorbonne University, the candidate will contribute to advancing the fundamental understanding of Fe-IM formation during solidification and possibly heat treatment, while helping identify pathways for industrial implementation.

Context & environment

The aluminium industry is facing increasing pressure to reduce its carbon footprint and support a circular economy through the increased use of post-consumer recycled scrap. However, higher recycled contents inevitably introduce larger concentrations of impurity elements, particularly Fe and Si, which promote the formation of brittle Fe-containing intermetallic phases that can negatively affect mechanical properties and processability.

The development of new generations of impurity-tolerant aluminium alloys therefore requires a deeper understanding of the mechanisms governing Fe-intermetallic nucleation, growth and transformation during solidification and subsequent thermal treatments.

This internship is part of a broader research programme launched in 2023 through an initial internship and currently pursued within a PhD collaboration between Constellium C-TEC (Voreppe, France) and Sorbonne University (Paris, France). The programme combines advanced experimental solidification studies with microstructural characterization to identify processing routes capable of controlling detrimental Fe-rich intermetallic phases in recycled aluminium alloys.

The candidate will spend his/her internship between Constellium C-TEC in Voreppe and Sorbonne University in Paris, providing a unique opportunity to work in both industrial and academic environments while contributing directly to an ongoing long-term research project.

The work will initially focus on model aluminium alloys and recycling-friendly alloy compositions relevant to future automotive and aerospace products. Special emphasis will be placed on understanding the influence of chemical composition and solidification conditions on Fe-IM nucleation and growth. The candidate will participate in alloy preparation, in situ solidification experiments and advanced microstructural characterization using optical and electron microscopy techniques.

In addition to investigating in situ Fe-IM formation during solidification, the internship could explore other complementary research directions such as:

Extension of the methodology developed for near-eutectic compositions to hypoeutectic alloys, with particular attention given to the nucleation and growth of secondary Fe-IM phases and to the interactions between the advancing FCC-Al solidification front and the formation of Fe-rich intermetallic compounds.
Investigation of the in-situ evolution of Fe-IMs during homogenization heat treatment, including the transformation of α-AlFeSi phases into β-AlFeSi phases, and the resulting impact on final intermetallic morphology and distribution. This approach will contribute to establishing links between casting conditions, as-solidified microstructure, and the microstructure after homogenization.
Assessment of pathways for upscaling the most promising microstructural control strategies toward laboratory-scale castings, followed by representative downstream thermomechanical processing and mechanical characterization. This will help quantify the influence of the observed microstructural modifications on final alloy performance and bridge the gap between fundamental understanding and industrial application.

The internship will be supervised by:

Dr. Georges Salloum-Abou-Jaoude

Constellium C-TEC, Voreppe, France

And

Prof. Sabine Bottin-Rousseau

Sorbonne Université, Paris, France

The candidate will spend part of the internship at Constellium C-TEC's R&D Centre in Voreppe to become familiar with the industrial challenges associated with aluminium alloy solidification and manufacturing. He/she will contribute to the production of novel recycling-friendly next-generation aluminium alloys. The candidate will then spend a significant portion of the internship at Sorbonne University in Paris, working with world-leading scientists in the field of aluminium eutectic phase nucleation and growth. At Sorbonne University, the candidate will contribute to the development and execution of in situ, real-time solidification experiments aimed at studying the effects of alloy chemistry, solidification parameters, and potentially homogenization treatments on the nucleation and growth of AlFeSi phases. The candidate will return periodically to C-TEC for post-mortem microstructural characterization and quantification using advanced techniques such as SEM and EBSD.

Expected results:

This internship decomposes into several stages:

Familiarization with the principle of solidification of metallic alloys
Familiarization with aluminium alloy production and direct chill casting
Manufacture recycling friendly model alloys, preparation of:
Experimental protocols
Quality inspection/investigation
Sample machining and preparation.
Familiarization with in situ and real time investigation of aluminium alloy solidification
Prepare aluminium samples using plasma sputtering
Perform in situ and real time experiments of aluminium alloy solidification
Data and image processing of solidification experiments
Analysis and reporting of the findings

Education level: Bac+5 / M.Sc.

Mechanical Engineering - Physics or Material Science

Competencies & technical & soft skills requirement:

Engineering student (last year) or Masters (M2) of Physics or Material Science
Candidate motivated, creative, rigorous, curious, good communication skills and autonomous.
Knowledge in Material science, and eager to develop experimental skills
Knowledge of Microsoft Office
Good communication skills in English and French are essential