Internship R&D - Modelling Damage Mechanisms in Recycled Aluminium Alloys

C-TEC INTERNSHIP OFFER 

Modelling Damage Mechanisms in Recycled Aluminium Alloys

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 : Modeling damage nucleation and growth in recycled aluminium alloys

Context 

Due to its low density, aluminium (Al) is a key material for sustainability as it allows lightweighting. In order to decrease the CO2 emissions associated with its production, it is required to massively use recycled aluminium, meaning remelting Al scrap to make new ingots. However, switching from primary synthesis (bauxite reduction) to secondary synthesis (scrap melting) often leads to increasing impurities, the main one being iron in aluminium. Such contaminants may impact the performance of the current alloys in terms of ductility/formability because they form brittle intermetallic particles within the aluminium matrix.

On the one hand, Constellium research center and Centre des Matériaux laboratory (Mines Paris - PSL) currently collaborate for a PhD work aiming at characterizing the link between damage development and intermetallics-related features (size, nature, spatial distribution…). For this, in-situ nano-tomography experiments at the synchrotron have been performed on different microstructures to simultaneously image voids and particles evolution while straining.    On the other hand, a cellular automaton model based on a micromechanical description of damage nucleation, growth and coalescence has been proposed some years ago by researchers at the Catholic University of Louvain (http://dx.doi.org/10.1016/j.actamat.2015.10.008). It is able to consider a large number of particles with their distribution of position, size and void nucleation stress and predicts the fracture strain.

Ojectives

The objective of the project is to implement, test and validate the model on newly generated nano-tomography data for 6xxx alloys for automotive applications and if needed, implement upgrades to better capture the observed mechanisms.

The project has several components :

• Literature review on failure mechanisms and existing modeling strategies 
• Post-treatment of nano-tomography scans to extract input data for the model
• Building of the initial representative volume element (RVE) to correctly describe the multi-phase materials of interest
• Test of the existing model and identification of potential discrepancies vs. experimental observations
• Implementation of the model (better description of some physical mechanisms may be proposed, additional features for both inputs and outputs)
• Comparison between simulation and experimental results in terms of fracture strain and location of damage initiation
• Synthesis of the results, report writing and presentation to the team
• Transfer to the industrial R&D center and training of engineers to use it 

The intern will be based in the laboratory of Centre des Matériaux, Mines Paris - PSL in the Paris region (Versailles). However, frequent interactions with  the industrial partner will take place together with technical exchanges with other cutting-edge academic modeling teams (UCL in Belgium, CEMEF in France) with experience in the ductile failure topic

Profile 

Education level : Engineering school or Master of Science

Competencies & technical & soft skills requirement :

• Good knowledge in mechanics
• Knowledge in physical metallurgy is a plus
• Motivation for numerical work
• Strong capacity to post-treat a significant amount of data from both simulations and experiments
• Serious, autonomy, critical mind and creativity
• Ability to interact with both academic and industrial partners
• Interest for research and development type of work
• Good level of the English language (both written and spoken)