Modifications physico-chimiques de poudres base-Ti pour la fabrication additive en vue de réduire l'empreinte environnementale // Physico-chemical modification of Ti-based powders for additive manufacturing to reduce environmental footprint

Le projet que nous proposons vise à élucider les modifications physico-chimiques que subissent les poudres métalliques d'alliages critiques à base de titane au cours de l'étape d'étuvage, que ces poudres soient issues d'un vieillissement ou d'un passage dans le bâti de fabrication. L'objectif à terme est de réutiliser ces poudres à haute valeur ajoutée pour limiter l'empreinte environnementale du procédé L-PBF.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Our proposed project aims to elucidate the physico-chemical changes that metal powders of critical titanium-based alloys undergo during the bake-out stage, whether these powders result from aging or from passage through the manufacturing rack. The ultimate aim is to reuse these high value-added powders to limit the environmental footprint of the L-PBF process.
First and foremost, we will adopt a four-stage experimental approach: (i) manufacture of new metal powders under optimal conditions, for characterization purposes, in order to gain the most accurate possible knowledge of the starting materials and powders for the study, i.e. Ti-6Al-4V and TiAl; (ii) heat treatment of Ti-based metal powders in order to reproduce the conditions of ageing and passage through the manufacturing frame. These heat treatments in the presence of H2O and/or O2 and/or N2 will give rise to physical phenomena and chemical reactions that will need to be studied kinetically and with respect to the corrosion products formed, which will be studied at nanometric scale (SEM, TEM, XPS, etc.); (iii) bake-out of the two selected alloys, and comparison of the pre-bake-out condition (new, aged, used) with the post-bake-out condition. The main objective of this task will then be to model the reactions taking place on the surface of the particles during steaming; (iv) critical analysis of the steaming step carried out with regard to the economic and environmental benefits and costs of this step (life cycle analysis).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Début de la thèse : 01/10/2025

Other public funding

ANR Financement d'Agences de financement de la recherche

Université Grenoble Alpes

510 I-MEP² - Ingénierie - Matériaux, Mécanique, Environnement, Energétique, Procédés, Production

Le·la candidat·e recherché·e devra posséder un diplôme de Master 2 à visée recherche ou équivalent dans le domaine de la science des matériaux, de la métallurgie ou encore en chimie minérale. Des connaissances en caractérisation des matériaux et/ou métallurgie et/ou cinétique sont attendues.
The successful candidate will have a Master 2 research degree or equivalent in materials science, metallurgy or inorganic chemistry. Knowledge of materials characterization and/or metallurgy and/or kinetics is expected.