Description du sujet de thèse

This thesis topic is part of the ANR X-FA2023 project (ref: ANR-23-CE51-0013), led by a consortium of two research laboratories, the Laboratory for the Study of Microstructures and Mechanics of Materials (LEM3) in Metz, the ENIT Production Engineering Laboratory (LGP-ENIT) in Tarbes, and the company AML Innovation in Norroy-Le-Veneur. Additive manufacturing (AM) is a revolutionary technology in modern manufacturing processes that has found a wide range of applications in many sectors: automotive, aerospace, medicine and beyond… However, although AM has opened a new era of opportunities, it is not without challenges. Surface irregularities such as partially fused particles, the "staircase" effect related to the stratification of print layers, the heterogeneity of printed substrates, structural anisotropy, cracks, and voids impair mechanical performance and fatigue resistance, and promote corrosion and premature wear of components. Given the limitations of this process, post-treatments have been developed to mitigate their effects and increase the performance of these printed structures. So-called "surface ablation" technologies have been extensively studied and developed. These include shot peening, mechanical and electrochemical polishing, as well as their combination in hybrid treatments, which involve removing the top surface layer. However, these methods are not suitable for/applicable to parts with complex shapes, require a long processing time, result in a non-uniform surface finish, may cause contamination of internal channels, and do not meet current environmental specifications. This study proposes an alternative technology for the post-processing of metal parts, resulting from additive manufacturing. This disruptive coating technology is based on the use of "slurry" - a liquid-based suspension containing powdered metals or metal alloys. This coating method has many advantages (functionalization of surfaces, coating of cavities with complex morphologies and small sizes, smoothing effect, sealing of internal cavities in connection with the surface, trapping detachable particles) Given these characteristics, an improvement in the fatigue characteristics of parts obtained by AM is strongly anticipated.

Contexte de travail

You will be enrolled in the doctoral school of the University of Lorraine (Chemistry - Mechanics - Materials - Physics: C2MP) and hosted at LEM3 in Metz and you will benefit from a CNRS doctoral contract, part of your thesis work will be carried out within AML Innovation (less than 20 minutes from LEM3).

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.

Contraintes et risques

screen work
chemical risks related to sample preparation