Mapping strain rate dependence of dislocation-defect interactions by atomistic simulations
Probing the mechanisms of defect–defect interactions at strain rates lower than 10[superscript 6] s[superscript −1] is an unresolved challenge to date to molecular dynamics (MD) techniques. Here we propose an original atomistic approach based on transition state theory and the concept of a strain-de...
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| Format: | Article |
| Language: | en_US |
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National Academy of Sciences (U.S.)
2014
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| Online Access: | http://hdl.handle.net/1721.1/89079 https://orcid.org/0000-0002-2688-5666 https://orcid.org/0000-0002-2727-0137 |
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| author | Fan, Yue Osetsky, Yuri N. Yip, Sidney Yildiz, Bilge |
| author2 | Massachusetts Institute of Technology. Department of Materials Science and Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Materials Science and Engineering Fan, Yue Osetsky, Yuri N. Yip, Sidney Yildiz, Bilge |
| author_sort | Fan, Yue |
| collection | MIT |
| description | Probing the mechanisms of defect–defect interactions at strain rates lower than 10[superscript 6] s[superscript −1] is an unresolved challenge to date to molecular dynamics (MD) techniques. Here we propose an original atomistic approach based on transition state theory and the concept of a strain-dependent effective activation barrier that is capable of simulating the kinetics of dislocation–defect interactions at virtually any strain rate, exemplified within 10[superscript −7] to 10[superscript 7] s[superscript −1]. We apply this approach to the problem of an edge dislocation colliding with a cluster of self-interstitial atoms (SIAs) under shear deformation. Using an activation–relaxation algorithm [Kushima A, et al. (2009) J Chem Phys 130:224504], we uncover a unique strain-rate–dependent trigger mechanism that allows the SIA cluster to be absorbed during the process, leading to dislocation climb. Guided by this finding, we determine the activation barrier of the trigger mechanism as a function of shear strain, and use that in a coarse-graining rate equation formulation for constructing a mechanism map in the phase space of strain rate and temperature. Our predictions of a crossover from a defect recovery at the low strain-rate regime to defect absorption behavior in the high strain-rate regime are validated against our own independent, direct MD simulations at 10[superscript 5] to 10[superscript 7] s[superscript −1]. Implications of the present approach for probing molecular-level mechanisms in strain-rate regimes previously considered inaccessible to atomistic simulations are discussed. |
| first_indexed | 2024-09-23T12:05:04Z |
| format | Article |
| id | mit-1721.1/89079 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T12:05:04Z |
| publishDate | 2014 |
| publisher | National Academy of Sciences (U.S.) |
| record_format | dspace |
| spelling | mit-1721.1/890792022-09-27T23:59:36Z Mapping strain rate dependence of dislocation-defect interactions by atomistic simulations Fan, Yue Osetsky, Yuri N. Yip, Sidney Yildiz, Bilge Massachusetts Institute of Technology. Department of Materials Science and Engineering Massachusetts Institute of Technology. Department of Nuclear Science and Engineering Fan, Yue Yip, Sidney Yildiz, Bilge Probing the mechanisms of defect–defect interactions at strain rates lower than 10[superscript 6] s[superscript −1] is an unresolved challenge to date to molecular dynamics (MD) techniques. Here we propose an original atomistic approach based on transition state theory and the concept of a strain-dependent effective activation barrier that is capable of simulating the kinetics of dislocation–defect interactions at virtually any strain rate, exemplified within 10[superscript −7] to 10[superscript 7] s[superscript −1]. We apply this approach to the problem of an edge dislocation colliding with a cluster of self-interstitial atoms (SIAs) under shear deformation. Using an activation–relaxation algorithm [Kushima A, et al. (2009) J Chem Phys 130:224504], we uncover a unique strain-rate–dependent trigger mechanism that allows the SIA cluster to be absorbed during the process, leading to dislocation climb. Guided by this finding, we determine the activation barrier of the trigger mechanism as a function of shear strain, and use that in a coarse-graining rate equation formulation for constructing a mechanism map in the phase space of strain rate and temperature. Our predictions of a crossover from a defect recovery at the low strain-rate regime to defect absorption behavior in the high strain-rate regime are validated against our own independent, direct MD simulations at 10[superscript 5] to 10[superscript 7] s[superscript −1]. Implications of the present approach for probing molecular-level mechanisms in strain-rate regimes previously considered inaccessible to atomistic simulations are discussed. United States. Dept. of Energy (Energy Innovation Hub for Modeling and Simulation of Nuclear Reactors Contract DE-AC05-00OR22725) 2014-08-28T13:56:42Z 2014-08-28T13:56:42Z 2013-10 2013-05 Article http://purl.org/eprint/type/JournalArticle 0027-8424 1091-6490 http://hdl.handle.net/1721.1/89079 Fan, Y., Y. N. Osetskiy, S. Yip, and B. Yildiz. “Mapping Strain Rate Dependence of Dislocation-Defect Interactions by Atomistic Simulations.” Proceedings of the National Academy of Sciences 110, no. 44 (October 10, 2013): 17756–17761. https://orcid.org/0000-0002-2688-5666 https://orcid.org/0000-0002-2727-0137 en_US http://dx.doi.org/10.1073/pnas.1310036110 Proceedings of the National Academy of Sciences Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf National Academy of Sciences (U.S.) PNAS |
| spellingShingle | Fan, Yue Osetsky, Yuri N. Yip, Sidney Yildiz, Bilge Mapping strain rate dependence of dislocation-defect interactions by atomistic simulations |
| title | Mapping strain rate dependence of dislocation-defect interactions by atomistic simulations |
| title_full | Mapping strain rate dependence of dislocation-defect interactions by atomistic simulations |
| title_fullStr | Mapping strain rate dependence of dislocation-defect interactions by atomistic simulations |
| title_full_unstemmed | Mapping strain rate dependence of dislocation-defect interactions by atomistic simulations |
| title_short | Mapping strain rate dependence of dislocation-defect interactions by atomistic simulations |
| title_sort | mapping strain rate dependence of dislocation defect interactions by atomistic simulations |
| url | http://hdl.handle.net/1721.1/89079 https://orcid.org/0000-0002-2688-5666 https://orcid.org/0000-0002-2727-0137 |
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