Interplay of plasticity and phase transformation in shock wave propagation in nanocrystalline iron
Strong shock waves create not only plasticity in Fe, but also phase transform the material from its bcc phase to the high-pressure hcp phase. We perform molecular-dynamics simulations of large, 8-million atom nanocrystalline Fe samples to study the interplay between these two mechanisms. We compare...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2014-01-01
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| Series: | New Journal of Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1367-2630/16/9/093032 |
| _version_ | 1797751124062633984 |
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| author | Nina Gunkelmann Diego R Tramontina Eduardo M Bringa Herbert M Urbassek |
| author_facet | Nina Gunkelmann Diego R Tramontina Eduardo M Bringa Herbert M Urbassek |
| author_sort | Nina Gunkelmann |
| collection | DOAJ |
| description | Strong shock waves create not only plasticity in Fe, but also phase transform the material from its bcc phase to the high-pressure hcp phase. We perform molecular-dynamics simulations of large, 8-million atom nanocrystalline Fe samples to study the interplay between these two mechanisms. We compare results for a potential that describes dislocation generation realistically but excludes phase change with another which in addition faithfully features the bcc → hcp transformation. With increasing shock strength, we find a transition from a two-wave structure (elastic and plastic wave) to a three-wave structure (an additional phase-transformation wave), in agreement with experiment. Our results demonstrate that the phase transformation is preceded by dislocation generation at the grain boundaries (GBs). Plasticity is mostly given by the formation of dislocation loops, which cross the grains and leave behind screw dislocations. We find that the phase transition occurs for a particle velocity between 0.6 and 0.7 km s ^−1 . The phase transition takes only about 10 ps, and the transition time decreases with increasing shock pressure. |
| first_indexed | 2024-03-12T16:43:53Z |
| format | Article |
| id | doaj.art-c4f62dd784164eddb39fbafbe13ce754 |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:43:53Z |
| publishDate | 2014-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-c4f62dd784164eddb39fbafbe13ce7542023-08-08T14:21:43ZengIOP PublishingNew Journal of Physics1367-26302014-01-0116909303210.1088/1367-2630/16/9/093032Interplay of plasticity and phase transformation in shock wave propagation in nanocrystalline ironNina Gunkelmann0Diego R Tramontina1Eduardo M Bringa2Herbert M Urbassek3Physics Department and Research Center OPTIMAS , University Kaiserslautern, Erwin-Schrödinger-Straße, D-67663 Kaiserslautern, Germany; Institute for Multiscale Simulations , Friedrich-Alexander-Universität, D-91052 Erlangen, GermanyFacultad de Ciencias Exactas y Naturales , Universidad Nacional de Cuyo, Mendoza M5502JMA, Argentina; Instituto de Bioingeniería , Universidad de Mendoza, Mendoza M5502BZG, ArgentinaFacultad de Ciencias Exactas y Naturales , Universidad Nacional de Cuyo, Mendoza M5502JMA, Argentina; Consejo Nacional de Investigaciones Cientìficas y Técnicas , CABA C1033AAJ, ArgentinaPhysics Department and Research Center OPTIMAS , University Kaiserslautern, Erwin-Schrödinger-Straße, D-67663 Kaiserslautern, GermanyStrong shock waves create not only plasticity in Fe, but also phase transform the material from its bcc phase to the high-pressure hcp phase. We perform molecular-dynamics simulations of large, 8-million atom nanocrystalline Fe samples to study the interplay between these two mechanisms. We compare results for a potential that describes dislocation generation realistically but excludes phase change with another which in addition faithfully features the bcc → hcp transformation. With increasing shock strength, we find a transition from a two-wave structure (elastic and plastic wave) to a three-wave structure (an additional phase-transformation wave), in agreement with experiment. Our results demonstrate that the phase transformation is preceded by dislocation generation at the grain boundaries (GBs). Plasticity is mostly given by the formation of dislocation loops, which cross the grains and leave behind screw dislocations. We find that the phase transition occurs for a particle velocity between 0.6 and 0.7 km s ^−1 . The phase transition takes only about 10 ps, and the transition time decreases with increasing shock pressure.https://doi.org/10.1088/1367-2630/16/9/093032shock waveironmolecular dynamicssolid-solid transitionsplasticitydislocations |
| spellingShingle | Nina Gunkelmann Diego R Tramontina Eduardo M Bringa Herbert M Urbassek Interplay of plasticity and phase transformation in shock wave propagation in nanocrystalline iron New Journal of Physics shock wave iron molecular dynamics solid-solid transitions plasticity dislocations |
| title | Interplay of plasticity and phase transformation in shock wave propagation in nanocrystalline iron |
| title_full | Interplay of plasticity and phase transformation in shock wave propagation in nanocrystalline iron |
| title_fullStr | Interplay of plasticity and phase transformation in shock wave propagation in nanocrystalline iron |
| title_full_unstemmed | Interplay of plasticity and phase transformation in shock wave propagation in nanocrystalline iron |
| title_short | Interplay of plasticity and phase transformation in shock wave propagation in nanocrystalline iron |
| title_sort | interplay of plasticity and phase transformation in shock wave propagation in nanocrystalline iron |
| topic | shock wave iron molecular dynamics solid-solid transitions plasticity dislocations |
| url | https://doi.org/10.1088/1367-2630/16/9/093032 |
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