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Microscopic Mechanism of Void Nucleation at Dislocation Boundaries: A Discrete Dislocation Dynamics Simulation Study
Ping Yang1, Wei Cai2, Pengyang Zhao1,*
1 Department of Engineering Mechanics, School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong
University, Shanghai, 200240, China
2 Department of Materials Science and Engineering, Stanford University, Palo Alto, CA 94305, USA
* Corresponding Author: Pengyang Zhao. Email:
The International Conference on Computational & Experimental Engineering and Sciences 2023, 26(1), 1-1. https://doi.org/10.32604/icces.2023.010400
Abstract
Void nucleation is of great significance in understanding ductile fracture of many important engineering
materials. Recent experiments have shown that voids are nucleated via vacancy condensation and
dislocation boundaries are the main nucleation sites. However, it is still unclear what role is played exactly
by dislocation boundaries in promoting void nucleation and what kind of defect configuration is involved.
Here we propose a new mechanism for dislocation boundary-induced void nucleation and develop
accordingly a vacancy condensation model based on the classical nucleation theory. The model suggests that
vacancy condensation to form void is impossible in the absence of external driving force and there is a
nonlinear negative correlation between the activation free energy barrier for void nucleation and the local
hydrostatic tensile stress. It is also shown that the relaxation of elastic strain energy of vacancies, absent in
the previous void nucleation models and introduced in ours, can greatly lower the activation energy barrier
and thus cannot be ignored. The kinetic feasibility of the newly proposed mechanism is examined and
explored using three-dimensional discrete dislocation dynamics simulations. Our simulation results show
that vacancy condensation occurs more likely near the dislocation boundary than in the dislocation cell and
the synergy of multiple dislocation pile-ups is the key to enabling dislocation boundaries to serve as the
preferential sites for void nucleation, which cannot be achieved by a single dislocation pile-up alone.
Cite This Article
APA Style
Yang, P., Cai, W., Zhao, P. (2023). Microscopic mechanism of void nucleation at dislocation boundaries: A discrete dislocation dynamics simulation study. The International Conference on Computational & Experimental Engineering and Sciences, 26(1), 1-1. https://doi.org/10.32604/icces.2023.010400
Vancouver Style
Yang P, Cai W, Zhao P. Microscopic mechanism of void nucleation at dislocation boundaries: A discrete dislocation dynamics simulation study. Int Conf Comput Exp Eng Sciences . 2023;26(1):1-1 https://doi.org/10.32604/icces.2023.010400
IEEE Style
P. Yang, W. Cai, and P. Zhao "Microscopic Mechanism of Void Nucleation at Dislocation Boundaries: A Discrete Dislocation Dynamics Simulation Study," Int. Conf. Comput. Exp. Eng. Sciences , vol. 26, no. 1, pp. 1-1. 2023. https://doi.org/10.32604/icces.2023.010400