PhD opportunities

Modeling intergranular damage assisted by oxidation in nickel-based superalloys

Thesis proposal

Area of expertiseMécanique
Doctoral SchoolISMME - Ingénierie des Systèmes, Matériaux, Mécanique, Énergétique
SupervisorFOREST Samuel
Research unitCentre des Matériaux
KeywordsCrystal plasticity, intergranular damage, oxidation, finite elements, phase field méthod
AbstractThe objective of the thesis is to develop a modelling and simulation tool capable of accounting, explicitly and in a coupled manner, for the phenomena of local damage (microcracks and microcavities) and oxidation in connection with the initiation and propagation of intergranular cracks. The support material of the study will be a nickel-based superalloy widely used for low-pressure turbine blades in aircraft engines. The first part consists in introducing a damage-coupled consitutive law for the grain boundary in order to reproduce different macroscopic damage kinetics depending on the fatigue and/or creep loading direction. The phase field method will be used for this purpose.

In a second part, a model coupling the diffusion of some chemical elements, the growth of a new phase (internal oxide) and the local thermomechanical behaviour of the heterogeneous medium will be constructed.

Finally, the modelling approach developed during the thesis will be compared with available experimental observations on (i) the kinetics of notching/pitting observed on the surface of the material and (ii) the effect of a high temperature dwell time on the kinetics of intergranular crack propagation.
ProfileEngineer and / or Master of Science - Good level of general and scientific culture. Good level of knowledge of French (B2 level in french is required) and English. (B2 level in english is required) Good analytical, synthesis, innovation and communication skills. Qualities of adaptability and creativity. Teaching skills. Motivation for research activity. Coherent professional project.

Prerequisite (specific skills for this thesis):

Thermomechanics of materials, computational mechanics, viscoplasticity, constitutive laws

Applicants should supply the following :
• a detailed resume
• a copy of the identity card or passport
• a covering letter explaining the applicant's motivation for the position
• detailed exam results
• two references : the name and contact details of at least two people who could be contacted
• to provide an appreciation of the candidate
• Your notes of M1, M2
• level of English equivalent TOEIC

to be sent to recrutement_these@mat.mines-paristech.fr
FundingContrat de recherche