Internship R&D - Modelling and Optimization of Aluminium Alloy Recycling

C-TEC INTERNSHIP OFFER 

Modelling and Optimization of Aluminium Alloy Recycling

Constellium is a world leader in the development and manufacture of high value-added aluminum products and solutions for a wide range of markets and applications, focusing in particular on aerospace, automotive and packaging. Constellium also has nearly 12,000 employees worldwide.We are committed to minimizing the environmental impact of our operations and improving the life cycle footprint of aluminum throughout the value chain.

In our company, safety is essential, it is one of our core values without compromise. Our Research and Technology Center, C-TEC Constellium Technology Center, based in Grenoble (Voreppe – 38) employs about 240 people. 

By joining our company, you will discover a multicultural company (over 20 nationalities) which is committed to diversity and the well-being of its employees.

Your mission : Modelling of Grain Refinement for Increasing Recycling of Aluminium alloys 

Main objective and key accountabilities 

Combine numerical and experimental techniques to understand the effect of the microstructural features of industrial grain refiners on their grain refining efficiency in aluminium alloys.

The knowledge generated in this work will contribute to incorporating higher recycled contents in the production of aluminium alloys for aerospace and automotive applications.

Context & environment

Aluminium alloys have long been crucial to the aerospace industry due to their low density and high mechanical properties.  Nowadays their use is rapidly expanding in the automotive sector for the purpose of light weighting vehicles for reducing the carbon footprint of the industry.

Grain size control during casting of aluminium alloys has always been essential to ensure sound cast quality and guarantee the desired properties of the final product. A non-reliable solidification microstructure control during direct chill (DC) casting reduces production yield, generating more runaround scrap and resulting in significant value loss. Our plants are more than ever seeking to reduce their runaround scrap to maximise external scrap content resulting in reduced carbon footprint. Equiaxed grains of well-controlled size help increase production yields by reducing the risk of hot tearing and shrinkage porosities in cast products. This results from enhanced liquid feeding between the solidifying α-Al grains.

Although grain refinement in aluminium alloys is well known from the fundamental and experimental point of view, grain size control is still not always guaranteed at the industrial scale. This depends largely on the nature and fabrication quality of the grain refiner rod. There are sometimes debates in the industrial community about what makes a grain refiner more or less efficient. We have concluded in recent findings, that the presence of nucleating particle agglomerates in industrial grain refiners has a significant negative impact on grain refiner efficiency. In the tested grain refiners, notable metallurgical differences were identified in nominally identical grain refiners coming from different suppliers and even between lots coming from the same supplier.  However, these differences have not yet been unequivocally linked to the resulting grain refining efficiencies of these different refiners. 

In this work, we aim to improve our understanding and perfect the already developed cellular automaton model that can establish a link between the grain refiner nucleant particle size distribution and grain refining efficiency and fading in aluminium alloys.

The internship will be supervised by :

Dr. Emmanuel Waz and Dr. Georges Salloum-Abou-Jaoude

Constellium C-TEC, Voreppe, France

Expected results

The candidate will begin by conducting cellular automaton simulations to explore the physical mechanisms influencing grain refiner efficiency. Depending on feasibility and available resources, these simulations may be complemented by experimental work at Constellium C-TEC, Voreppe, including solidification trials and optical/SEM characterizations. The aim would be to quantify the size distribution of nucleant particles and other metallurgical features, and to assess how well the simulation results align with experimental observations. The final goal is to deliver a reliable grain size prediction model that could be used by Constellium.

This internship can be decomposed into several stages

• Familiarization with the principles of solidification of metallic alloys
• Familiarization with the cellular automaton model
• Take into consideration the globular to dendritic transition during the growth of aluminium grains
• Study the effect of grain refiner type/nature on the final grain size
• Study the effect of nucleant particle size distribution on the final solidified microstructure
• Use numerical modelling to propose improved specifications on grain refiners for aluminium alloys

Profile 

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