CIRIMAT – Post-doctoral position (H/F) – June, 2022
Development of a robust industrial chromium electrolytic deposition process for
aeronautics
Location: CIRIMAT – Centre Interuniversitaire de Recherche et d’Ingénierie des Matériaux
Funding: the applicant will be employed by the Toulouse III University as part of a collaborative project with
Liebherr and Mecaprotec Industries.
Gross salary: ~2600 to 3200€ gross monthly depending on experience.
Start of contract and duration: November 2022, duration 24 months
Keywords: hard chromium plating; analytical chemistry; electrochemistry; aeronautics.
Description of the project
A doubling of the number of air passengers over the next twenty years, as well as a virtual doubling of the worldfleet, by 2039 are related to Medium-haul single-aisle aircraft will represent the main drivers of this growth, with 32,000 deliveries planned over twenty years.
In this context, the design of future single-aisle aircraft will face two major challenges. On the one hand, the increase in air traffic requires the reduction of the environmental footprint by reducing CO2 / NOx emissions and noise. On the other hand, the actors of the aeronautical sector have the objective of reducing the cost of operation per passenger. With this in mind, engine manufacturers are developing new generations of turbojets that will bring savings in fuel consumption of between 5 and 10%. As for the air systems—ensuring the supply of fresh air and the regulation of cabin pressure—constitute the largest consumers of non-propulsion energy. Thus, the objective is to design an optimized air system, with regard to energy consumption, which involves the development of innovative technologies and processes. One of the locks to be lifted is the realization of an electrolytic hard chrome plating of the valve body, in order to protect them from wear linked to the friction of the butterfly. The process developed involves the use of trivalent chromium instead of chromium trioxide, a substance currently used, classified as CMR and covered by the REACH regulations. However, the process based on trivalent chromium is not yet sufficiently robust, in particular concerning the
stability of the electrolytic baths during their use. Their properties tend to degrade over time. On the other hand, the quality of the deposits obtained depends strongly on the geometry of the part to be coated and on the temperature.
The objective being to design a robust and industrial process of electrolytic deposition on valve based on trivalent chromium, it is necessary to reinforce the control and the robustness of the process. For this, it is necessary to ensure the durability of the performance of the deposits during the aging of the bath, to adapt the treatment process (surface preparation, assembly of parts, tools, etc.) to the needs of various demonstrators (geometry of parts, areas to be chromed, operating conditions).
The recruited person will be involved in the following areas:
Evolution of the chemistry of samples from electrolysis baths at different stages of aging.
Monitoring of the free complexing agent concentration in aging baths.
Identification of degradation products
a. Identification of chromium complexes at the substrate/electrolyte interface and study of
chromium deposition mechanisms
b. Understand and identify the complexes and/or chemical species forming at the interface during
electrolysis at different stages of bath aging
Influence on deposit mechanisms during bath aging
Work context
The post-doctoral student will join the CIRIMAT “Coatings and Surface Treatments” team under the direction of P.-L. Taberna (DR CNRS) and M.-J. Menu (PR). The RTS team has significant expertise and knowledge in the field of analytical chemistry and electrochemistry. This work will be developed as part of a collaborative research program between Liebherr and Mecaprotec Industries.
The recruitment of the selected candidate is subject to validation by the “Defense Security Officer”.
Additional informations : Profile and skills sought
We are looking for a candidate with a PhD in analytical chemistry, electrochemistry or materials science. Preferably with experience in the production of electrolytic deposits. He (she) must be strongly motivated for experimentation and autonomous in the classic synthesis and characterization techniques used in analytical
chemistry and electrochemistry: UV spectroscopy, capillary electrophoresis, voltammetry, chronopotentiometry, etc. For any additional information on the project and/or the recruitment process, contact Pierre-Louis Taberna (pierre-louis.taberna@univ-tlse3.fr).
The application file, consisting of the following elements: a detailed CV and a cover letter with at least the name of a referent or letter of recommendation, must be sent to pierre-louis.taberna@univ-tlse3.fr and mariejoelle. menu@univ-tlse3.fr. Please put in the subject of the email “Post-doc Cr”.