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Title: Validation of the Concurrent Atomistic-Continuum Method on Screw Dislocation/Stacking Fault Interactions

Abstract

Dislocation/stacking fault interactions play an important role in the plastic deformation of metallic nanocrystals and polycrystals. These interactions have been explored in atomistic models, which are limited in scale length by high computational cost. In contrast, multiscale material modeling approaches have the potential to simulate the same systems at a fraction of the computational cost. In this paper, we validate the concurrent atomistic-continuum (CAC) method on the interactions between a lattice screw dislocation and a stacking fault (SF) in three face-centered cubic metallic materials—Ni, Al, and Ag. Two types of SFs are considered: intrinsic SF (ISF) and extrinsic SF (ESF). For the three materials at different strain levels, two screw dislocation/ISF interaction modes (annihilation of the ISF and transmission of the dislocation across the ISF) and three screw dislocation/ESF interaction modes (transformation of the ESF into a three-layer twin, transformation of the ESF into an ISF, and transmission of the dislocation across the ESF) are identified. Here, our results show that CAC is capable of accurately predicting the dislocation/SF interaction modes with greatly reduced DOFs compared to fully-resolved atomistic simulations.

Authors:
ORCiD logo [1];  [2];  [3];  [1]
  1. Georgia Inst. of Technology, Atlanta, GA (United States)
  2. Iowa State Univ., Ames, IA (United States)
  3. Univ. of Florida, Gainesville, FL (United States)
Publication Date:
Research Org.:
Georgia Inst. of Technology, Atlanta, GA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1420451
Alternate Identifier(s):
OSTI ID: 1393503
Grant/Contract Number:
SC0006539
Resource Type:
Journal Article: Published Article
Journal Name:
Crystals
Additional Journal Information:
Journal Volume: 7; Journal Issue: 5; Journal ID: ISSN 2073-4352
Publisher:
MDPI
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; dislocation; stacking fault; concurrent atomistic-continuum method

Citation Formats

Xu, Shuozhi, Xiong, Liming, Chen, Youping, and McDowell, David L. Validation of the Concurrent Atomistic-Continuum Method on Screw Dislocation/Stacking Fault Interactions. United States: N. p., 2017. Web. doi:10.3390/cryst7050120.
Xu, Shuozhi, Xiong, Liming, Chen, Youping, & McDowell, David L. Validation of the Concurrent Atomistic-Continuum Method on Screw Dislocation/Stacking Fault Interactions. United States. doi:10.3390/cryst7050120.
Xu, Shuozhi, Xiong, Liming, Chen, Youping, and McDowell, David L. Wed . "Validation of the Concurrent Atomistic-Continuum Method on Screw Dislocation/Stacking Fault Interactions". United States. doi:10.3390/cryst7050120.
@article{osti_1420451,
title = {Validation of the Concurrent Atomistic-Continuum Method on Screw Dislocation/Stacking Fault Interactions},
author = {Xu, Shuozhi and Xiong, Liming and Chen, Youping and McDowell, David L.},
abstractNote = {Dislocation/stacking fault interactions play an important role in the plastic deformation of metallic nanocrystals and polycrystals. These interactions have been explored in atomistic models, which are limited in scale length by high computational cost. In contrast, multiscale material modeling approaches have the potential to simulate the same systems at a fraction of the computational cost. In this paper, we validate the concurrent atomistic-continuum (CAC) method on the interactions between a lattice screw dislocation and a stacking fault (SF) in three face-centered cubic metallic materials—Ni, Al, and Ag. Two types of SFs are considered: intrinsic SF (ISF) and extrinsic SF (ESF). For the three materials at different strain levels, two screw dislocation/ISF interaction modes (annihilation of the ISF and transmission of the dislocation across the ISF) and three screw dislocation/ESF interaction modes (transformation of the ESF into a three-layer twin, transformation of the ESF into an ISF, and transmission of the dislocation across the ESF) are identified. Here, our results show that CAC is capable of accurately predicting the dislocation/SF interaction modes with greatly reduced DOFs compared to fully-resolved atomistic simulations.},
doi = {10.3390/cryst7050120},
journal = {Crystals},
number = 5,
volume = 7,
place = {United States},
year = {Wed Apr 26 00:00:00 EDT 2017},
month = {Wed Apr 26 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.3390/cryst7050120

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  • Dislocation/stacking fault interactions play an important role in the plastic deformation of metallic nanocrystals and polycrystals. These interactions have been explored in atomistic models, which are limited in scale length by high computational cost. In contrast, multiscale material modeling approaches have the potential to simulate the same systems at a fraction of the computational cost. In this paper, we validate the concurrent atomistic-continuum (CAC) method on the interactions between a lattice screw dislocation and a stacking fault (SF) in three face-centered cubic metallic materials—Ni, Al, and Ag. Two types of SFs are considered: intrinsic SF (ISF) and extrinsic SF (ESF).more » For the three materials at different strain levels, two screw dislocation/ISF interaction modes (annihilation of the ISF and transmission of the dislocation across the ISF) and three screw dislocation/ESF interaction modes (transformation of the ESF into a three-layer twin, transformation of the ESF into an ISF, and transmission of the dislocation across the ESF) are identified. Here, our results show that CAC is capable of accurately predicting the dislocation/SF interaction modes with greatly reduced DOFs compared to fully-resolved atomistic simulations.« less
  • Cited by 24
  • Stacking fault tetrahedra (SFTs) are formed under irradiation in fcc metals and alloys. The high number density of SFTs observed suggests that they should contribute to radiation-induced hardening and, therefore, be taken into account when estimating mechanical property changes of irradiated materials. The key issue in this is to describe the interaction between a moving dislocation and an individual SFT, which is distinguished by a small physical size of the order of {approx}1-10 nm. We have performed atomistic simulations of edge and screw dislocations interacting with SFTs of different sizes at different temperatures and strain rates. Five possible interaction outcomesmore » have been identified, involving either partial absorption, or shearing or restoration of SFTs. The mechanisms that give rise to these processes are described and their dependence on interaction parameters, such as SFT size, dislocation-SFT geometry, temperature and stress/strain rate are determined. Mechanisms that help to explain the formation of defect-free channels cleared by gliding dislocations, as observed experimentally, are also discussed. Hardening due to the various mechanisms and their dependence on loading conditions will be presented in a following paper (Part II).« less
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