(M/F) PhD - Gas-phase synthesis of nanolamellar aluminium carbonitrides for aerospace applications

Job Description

Thesis Subject

Ceramic Matrix Composites (CMCs) are heterogeneous materials composed of a matrix and reinforcements, established as high-performance materials for extreme environments due to their exceptional high-temperature resistance, low density, and mechanical durability. Indeed, they offer the potential to significantly improve the energy efficiency of jet engines and reduce CO₂ emissions, particularly through the use of hydrogen as a fuel. These materials are also increasingly gaining traction in the aerospace propulsion market, notably through the development of ultra-high-temperature CMCs (UHTCMCs). However, to fully capture these markets, new components—such as oxidation protection systems—are required to continue enhancing CMC performance. To achieve this, it is essential to explore novel ceramic materials, paving the way for a new generation of CMCs.

In this context, the ATHENA project aims to develop new nanolamellar compounds based on aluminium carbonitrides, represented by the general formula (AlN)ₙAl₄C₃. This little-studied family of materials holds untapped potential, primarily due to the challenges associated with synthesizing these compounds via solid-state routes. The thesis objective is therefore to synthesize and characterize (AlN)ₙAl₄C₃ compounds (where n = 1, 2, 3, and/or 4) using magnetron sputtering.

Magnetron sputtering provides precise control over composition, microstructure, and interfaces, enabling the design of compounds with predefined stoichiometries and various micro/nanostructures. The methodology employed during the thesis will involve implementing reactive and non-reactive sputtering protocols to define the formation mechanisms of compounds from the (AlN)ₙAl₄C₃ family. The overarching goal is to correlate the process with the structure, composition, and microstructure of the resulting thin films, and then with key properties such as hardness, substrate adhesion, thermal expansion coefficient, thermal conductivity, and oxidation resistance. This comprehensive study will improve the understanding of the phase stability of (AlN)ₙAl₄C₃ compounds and their potential as oxidation protection systems.

The thesis therefore aims to address the following questions:
1. Which process should be implemented to favor a specific (AlN)ₙAl₄C₃ stoichiometry over another?
2. What are the formation mechanisms of these compounds with respect to the synthesis conditions used?
3. What is the thermal and chemical stability, as well as the thermomechanical properties, of these compounds, and how do they vary with stoichiometry and microstructure?

Your Work Environment

The LCTS (Laboratoire des Composites ThermoStructuraux) is a laboratory located on the Bordeaux campus. It is a joint research unit of CNRS, the University of Bordeaux, Safran Group, and CEA. With 38 years of upstream research on refractory composites, it specializes in high-performance materials used in aviation, space, and energy sectors. The lab is organized in a single team operating in project mode in close partnership with its non-academic stakeholders. Currently, it comprises 34 permanent staff members, about fifteen PhD students, and 6 post-doctoral researchers.

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

The research professions