skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

This content will become publicly available on December 10, 2020

Title: A phase field model for dislocations in hexagonal close packed crystals

Abstract

In this work, an application of a phase field formulation suitable for modeling the motion of individual partial and full dislocations in hexagonal close packed (HCP) crystals is presented. The formulation incorporates periodic potentials for glide on the distinct HCP slip systems, which are informed here by density functional theory (DFT). The model is applied to simulate the dissociation process starting from an unstable perfect dislocation and ending at its final equilibrium structure for different slip planes and in different HCP metals. The structural characteristics that are predicted for these dislocations include the partial Burgers vectors, dissociation distances, core widths of the partials, and any asymmetries in these quantities. Mg is selected as one of the model materials since its dislocations are the most well studied and it is nearly elastically isotropic. For Mg, it is shown that the predictions for dissociation distances agree with those reported previously by atomic-scale calculations, including density functional theory, for dislocations on the basal < a >, prismatic < a >, and pyramidal type II slip systems. Furthermore, phase field model results are also presented for dislocations in Ti and Zr, which we find develop distinctively different equilibrium structures than Mg.

Authors:
ORCiD logo [1]; ORCiD logo [2];  [2];  [1]
  1. Univ. of California, Santa Barbara, CA (United States)
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1579701
Report Number(s):
LA-UR-19-26980
Journal ID: ISSN 0022-5096
Grant/Contract Number:  
89233218CNA000001; NSF CMMI-1729887; DMR-1121053
Resource Type:
Accepted Manuscript
Journal Name:
Journal of the Mechanics and Physics of Solids
Additional Journal Information:
Journal Volume: 137; Journal ID: ISSN 0022-5096
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; Phase field modeling; HCP metals; Partial dislocations; Stacking faults

Citation Formats

Albrecht-Weaver, Claire, Hunter, Abigail, Kumar, Anil, and Beyerlein, Irene Jane. A phase field model for dislocations in hexagonal close packed crystals. United States: N. p., 2019. Web. doi:10.1016/j.jmps.2019.103823.
Albrecht-Weaver, Claire, Hunter, Abigail, Kumar, Anil, & Beyerlein, Irene Jane. A phase field model for dislocations in hexagonal close packed crystals. United States. doi:10.1016/j.jmps.2019.103823.
Albrecht-Weaver, Claire, Hunter, Abigail, Kumar, Anil, and Beyerlein, Irene Jane. Tue . "A phase field model for dislocations in hexagonal close packed crystals". United States. doi:10.1016/j.jmps.2019.103823.
@article{osti_1579701,
title = {A phase field model for dislocations in hexagonal close packed crystals},
author = {Albrecht-Weaver, Claire and Hunter, Abigail and Kumar, Anil and Beyerlein, Irene Jane},
abstractNote = {In this work, an application of a phase field formulation suitable for modeling the motion of individual partial and full dislocations in hexagonal close packed (HCP) crystals is presented. The formulation incorporates periodic potentials for glide on the distinct HCP slip systems, which are informed here by density functional theory (DFT). The model is applied to simulate the dissociation process starting from an unstable perfect dislocation and ending at its final equilibrium structure for different slip planes and in different HCP metals. The structural characteristics that are predicted for these dislocations include the partial Burgers vectors, dissociation distances, core widths of the partials, and any asymmetries in these quantities. Mg is selected as one of the model materials since its dislocations are the most well studied and it is nearly elastically isotropic. For Mg, it is shown that the predictions for dissociation distances agree with those reported previously by atomic-scale calculations, including density functional theory, for dislocations on the basal < a >, prismatic < a >, and pyramidal type II slip systems. Furthermore, phase field model results are also presented for dislocations in Ti and Zr, which we find develop distinctively different equilibrium structures than Mg.},
doi = {10.1016/j.jmps.2019.103823},
journal = {Journal of the Mechanics and Physics of Solids},
number = ,
volume = 137,
place = {United States},
year = {2019},
month = {12}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on December 10, 2020
Publisher's Version of Record

Save / Share: