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Title: Anisotropy and Strain Localization in Dynamic Impact Experiments of Tantalum Single Crystals

Deformation mechanisms in bcc metals, especially in dynamic regimes, show unusual complexity, which complicates their use in high-reliability applications. Here, we employ novel, high-velocity cylinder impact experiments to explore plastic anisotropy in single crystal specimens under high-rate loading. The bcc tantalum single crystals exhibit unusually high deformation localization and strong plastic anisotropy when compared to polycrystalline samples. Several impact orientations - [100], [110], [111] and [1¯49] - are characterized over a range of impact velocities to examine orientation-dependent mechanical behavior versus strain rate. Moreover, the anisotropy and localized plastic strain seen in the recovered cylinders exhibit strong axial symmetries which differed according to lattice orientation. Two-, three-, and four-fold symmetries are observed. We propose a simple crystallographic argument, based on the Schmid law, to understand the observed symmetries. These tests are the first to explore the role of single-crystal orientation in Taylor impact tests and they clearly demonstrate the importance of crystallography in high strain rate and temperature deformation regimes. These results provide critical data to allow dramatically improved high-rate crystal plasticity models and will spur renewed interest in the role of crystallography to deformation in dynamics regimes.
Authors:
 [1] ;  [1] ;  [1] ;  [2] ;  [1] ;  [1]
  1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Report Number(s):
SAND-2018-9911J
Journal ID: ISSN 2045-2322; 667749
Grant/Contract Number:
AC04-94AL85000
Type:
Accepted Manuscript
Journal Name:
Scientific Reports
Additional Journal Information:
Journal Volume: 8; Journal Issue: 1; Journal ID: ISSN 2045-2322
Publisher:
Nature Publishing Group
Research Org:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE
OSTI Identifier:
1473946

Lim, Hojun, Carroll, Jay D., Battaile, Corbett C., Chen, Shuh Rong, Moore, Alexander P., and Lane, J. Matthew D.. Anisotropy and Strain Localization in Dynamic Impact Experiments of Tantalum Single Crystals. United States: N. p., Web. doi:10.1038/s41598-018-23879-1.
Lim, Hojun, Carroll, Jay D., Battaile, Corbett C., Chen, Shuh Rong, Moore, Alexander P., & Lane, J. Matthew D.. Anisotropy and Strain Localization in Dynamic Impact Experiments of Tantalum Single Crystals. United States. doi:10.1038/s41598-018-23879-1.
Lim, Hojun, Carroll, Jay D., Battaile, Corbett C., Chen, Shuh Rong, Moore, Alexander P., and Lane, J. Matthew D.. 2018. "Anisotropy and Strain Localization in Dynamic Impact Experiments of Tantalum Single Crystals". United States. doi:10.1038/s41598-018-23879-1. https://www.osti.gov/servlets/purl/1473946.
@article{osti_1473946,
title = {Anisotropy and Strain Localization in Dynamic Impact Experiments of Tantalum Single Crystals},
author = {Lim, Hojun and Carroll, Jay D. and Battaile, Corbett C. and Chen, Shuh Rong and Moore, Alexander P. and Lane, J. Matthew D.},
abstractNote = {Deformation mechanisms in bcc metals, especially in dynamic regimes, show unusual complexity, which complicates their use in high-reliability applications. Here, we employ novel, high-velocity cylinder impact experiments to explore plastic anisotropy in single crystal specimens under high-rate loading. The bcc tantalum single crystals exhibit unusually high deformation localization and strong plastic anisotropy when compared to polycrystalline samples. Several impact orientations - [100], [110], [111] and [1¯49] - are characterized over a range of impact velocities to examine orientation-dependent mechanical behavior versus strain rate. Moreover, the anisotropy and localized plastic strain seen in the recovered cylinders exhibit strong axial symmetries which differed according to lattice orientation. Two-, three-, and four-fold symmetries are observed. We propose a simple crystallographic argument, based on the Schmid law, to understand the observed symmetries. These tests are the first to explore the role of single-crystal orientation in Taylor impact tests and they clearly demonstrate the importance of crystallography in high strain rate and temperature deformation regimes. These results provide critical data to allow dramatically improved high-rate crystal plasticity models and will spur renewed interest in the role of crystallography to deformation in dynamics regimes.},
doi = {10.1038/s41598-018-23879-1},
journal = {Scientific Reports},
number = 1,
volume = 8,
place = {United States},
year = {2018},
month = {4}
}