Metals under extreme conditions (high stress, high temperature, high flux of radiations, etc.) exhibit extended defects such as dislocations and cavities whose interactions and evolutions dictate the macroscopic response of the whole material. However, because of their multi-physics aspects, the underlying phenomena are difficult to characterize, either by numerical simulations or by experimental approaches. Therefore, there is a need to develop efficient and physically justified numerical tools that are able to tackle such problems.

In this work, we propose a phase-field model that couples vacancy diffusion, dislocation climb and pore evolution [1]. This model naturally accounts for the elastic interactions between the objects and guarantees through variational constraints that matter is conserved when vacancies are exchanged [2].

In a first part, we will present the model and provide some details about its numerical implementation that include an improved solver for the equation controlling the vacancy field evolution. We will show that the use of this solver drastically increases the accessible diffusion time scale, allowing us to perform efficient mesoscopic simulations. In a second part, we will validate the phase-field model by comparing numerical results of elementary systems with known analytical results. In a third and last part, we will presents results from 2D-simulations of climbing dislocations interacting with an assembly of cavities, highlighting a significant role of elastic interactions on the microstructural evolution.

References
[1] B. Dabas. PhD Thesis of Sorbonne University, 2022.
[2] P. A. Geslin, B. Appolaire, A. Finel. Applied Physics Letters, 2014, 104(1), 011903.