Modélisation et simulation de l’impact de l’orientation de la structure microscopique d’un matériau métallique dans un processus de conduction thermique

Abstract

The phenomenon of thermal conduction is one of the most important physical phenomena in the aerospace industry, both during the lifetime of a carrier part and during its manufacturing/treatment process. Mostly, this phenomenon is modeled via an isotropic diffusion equation. However, in some particular contexts, such as in the case of parts having undergone a work hardening, it is possible to observe an elongation of the grains characterizing their crystallographic structure which induces a property of anisotropy to the system. It has been proven that the boundary between two grains represents a thermal barrier. This characteristic raises the question of the impact of the microstructure on the thermal conduction phenomenon. This project develops an innovative multi-scale model that takes into account the orientation of the microstructure specific to metallic materials. More precisely, the granular orientation, the atomic orientation and the variability of the thermal resistance at the boundaries according to the differences of atomic orientation on both sides of the barrier, were implemented. It was then necessary to test and implement different numerical methods to cope with the nonlinear and anisotropic characters of our diffusion model. Thus, we highlight the variations that the thermal field can undergo during a conduction process depending on the different microstructural contexts. It is through numerical campaigns, based on finite difference approaches, that we highlight the concrete impact of the microstructure on this phenomenon. Moreover, numerical observations have shown that the granular orientation is the parameter that dominates the impact of the microstructure. Finally, an experimental campaign is conducted to support the numerical observations. It presents a robust protocol to measure the impact of the granular orientation on the conductivity of a material.

Date	30 Nov 2022
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Sylvain G. Cloutier (Supervisor) & TestPrenomExterne TestNomExterne (Co-supervisor)