Speaker
Description
The comprehension of fundamental mechanisms leading to the formation and evolution of extended defects such as dislocation loops and cavities is crucial to understand the behaviour of materials under extreme conditions [1,2]. Underlying phenomena are hard to capture, either by numerical simulations or by experimental approaches. Thus building a complete mathematical formalism which can be efficiently implemented is at stake.
In this work we develop a phase-field variational model drawn from [3] that couples vacancy diffusion, dislocation climb and pore evolution, with the consideration of elastic interactions.
We will present the model and its specificities, including an improved solver on the equation controlling the vacancy concentration field, which drastically decreases the computational time required to perform the simulations. We will also present a way to physically control the accumulation of vacancies inside pores of small curvature radius.
Simulation results on the interactions between climbing dislocation loops and pores will be exposed, revealing the role of elastic interactions on the microstructural evolution. The influence of elasticity on the vacancy-induced pore closure will also be shown.
REFERENCES
[1] A.I. Epishin, B.S. Bokstein, I.L. Svetlov, et al. A Vacancy Model of Pore Annihilation During Hot Isostatic Pressing of Single Crystals of Nickel-Base Superalloys. Inorg. Mater. Appl. Res. (2018) 9: 57. https://doi.org/10.1134/S2075113318010100
[2] P. C. Millet and A. El-Azabal, Phase-field simulation of irradiated metals. Part II: Gas bubble kinetics, Comput. Mater. Sci. 50, 960-970 (2011).
[3] P. A. Geslin, B. Appolaire and A. Finel, A phase field model for dislocation climb, Appl. Phys. Lett. 104, 011903 (2014).
| Speaker Country | France |
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