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Title: Modeling the effect of neighboring grains on twin growth in HCP polycrystals

In this paper, we study the dependence of neighboring grain orientation on the local stress state around a deformation twin in a hexagonal close packed (HCP) crystal and its effects on the resistance against twin thickening. We use a recently developed, full-field elasto-visco-plastic formulation based on fast Fourier transforms that accounts for the twinning shear transformation imposed by the twin lamella. The study is applied to Mg, Zr and Ti, since these HCP metals tend to deform by activation of different types of slip modes. The analysis shows that the local stress along the twin boundary are strongly controlled by the relative orientation of the easiest deformation modes in the neighboring grain with respect to the twin lamella in the parent grain. A geometric expression that captures this parent-neighbor relationship is proposed and incorporated into a larger scale, mean-field visco-plastic self-consistent model to simulate the role of neighboring grain orientation on twin thickening. We demonstrate that the approach improves the prediction of twin area fraction distribution when compared with experimental observations.
Authors:
 [1] ;  [2] ;  [1] ;  [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  2. Univ. of California, Santa Barbara, CA (United States)
Publication Date:
Report Number(s):
LA-UR-17-21482
Journal ID: ISSN 0965-0393
Grant/Contract Number:
AC52-06NA25396
Type:
Accepted Manuscript
Journal Name:
Modelling and Simulation in Materials Science and Engineering
Additional Journal Information:
Journal Volume: 25; Journal Issue: 6; Journal ID: ISSN 0965-0393
Publisher:
IOP Publishing
Research Org:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE Office of Science (SC). Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; deformation twinning; HCP metals; shear transformation; backstress; twin growth
OSTI Identifier:
1406209

Kumar, M. Arul, Beyerlein, I. J., Lebensohn, R. A., and Tomé, C. N.. Modeling the effect of neighboring grains on twin growth in HCP polycrystals. United States: N. p., Web. doi:10.1088/1361-651X/aa7bbb.
Kumar, M. Arul, Beyerlein, I. J., Lebensohn, R. A., & Tomé, C. N.. Modeling the effect of neighboring grains on twin growth in HCP polycrystals. United States. doi:10.1088/1361-651X/aa7bbb.
Kumar, M. Arul, Beyerlein, I. J., Lebensohn, R. A., and Tomé, C. N.. 2017. "Modeling the effect of neighboring grains on twin growth in HCP polycrystals". United States. doi:10.1088/1361-651X/aa7bbb. https://www.osti.gov/servlets/purl/1406209.
@article{osti_1406209,
title = {Modeling the effect of neighboring grains on twin growth in HCP polycrystals},
author = {Kumar, M. Arul and Beyerlein, I. J. and Lebensohn, R. A. and Tomé, C. N.},
abstractNote = {In this paper, we study the dependence of neighboring grain orientation on the local stress state around a deformation twin in a hexagonal close packed (HCP) crystal and its effects on the resistance against twin thickening. We use a recently developed, full-field elasto-visco-plastic formulation based on fast Fourier transforms that accounts for the twinning shear transformation imposed by the twin lamella. The study is applied to Mg, Zr and Ti, since these HCP metals tend to deform by activation of different types of slip modes. The analysis shows that the local stress along the twin boundary are strongly controlled by the relative orientation of the easiest deformation modes in the neighboring grain with respect to the twin lamella in the parent grain. A geometric expression that captures this parent-neighbor relationship is proposed and incorporated into a larger scale, mean-field visco-plastic self-consistent model to simulate the role of neighboring grain orientation on twin thickening. We demonstrate that the approach improves the prediction of twin area fraction distribution when compared with experimental observations.},
doi = {10.1088/1361-651X/aa7bbb},
journal = {Modelling and Simulation in Materials Science and Engineering},
number = 6,
volume = 25,
place = {United States},
year = {2017},
month = {8}
}