Dislocation Nucleation on Grain Boundaries: Low Angle Twist and Asymmetric Tilt Boundaries
We investigate the mechanisms of incipient plasticity at low angle twist and asymmetric tilt boundaries in fcc metals. To observe plasticity of grain boundaries independently of the bulk plasticity, we simulate nanoindentation of bicrystals. On the low angle twist boundaries, the intrinsic grain bou...
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| Format: | Article |
| Language: | English |
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MDPI AG
2016-07-01
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| Series: | Crystals |
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| Online Access: | http://www.mdpi.com/2073-4352/6/7/77 |
| _version_ | 1811187166260232192 |
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| author | Erman Guleryuz Sinisa Dj. Mesarovic |
| author_facet | Erman Guleryuz Sinisa Dj. Mesarovic |
| author_sort | Erman Guleryuz |
| collection | DOAJ |
| description | We investigate the mechanisms of incipient plasticity at low angle twist and asymmetric tilt boundaries in fcc metals. To observe plasticity of grain boundaries independently of the bulk plasticity, we simulate nanoindentation of bicrystals. On the low angle twist boundaries, the intrinsic grain boundary (GB) dislocation network deforms under load until a dislocation segment compatible with glide on a lattice slip plane is created. The half loops are then emitted into the bulk of the crystal. Asymmetric twist boundaries considered here did not produce bulk dislocations under load. Instead, the boundary with a low excess volume nucleated a mobile GB dislocation and additional GB defects. The GB sliding proceeded by motion of the mobile GB dislocation. The boundary with a high excess volume sheared elastically, while bulk-nucleated dislocations produced plastic relaxation. |
| first_indexed | 2024-04-11T13:57:37Z |
| format | Article |
| id | doaj.art-f5f84f72931141f6918f4c061c336bf8 |
| institution | Directory Open Access Journal |
| issn | 2073-4352 |
| language | English |
| last_indexed | 2024-04-11T13:57:37Z |
| publishDate | 2016-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Crystals |
| spelling | doaj.art-f5f84f72931141f6918f4c061c336bf82022-12-22T04:20:13ZengMDPI AGCrystals2073-43522016-07-01677710.3390/cryst6070077cryst6070077Dislocation Nucleation on Grain Boundaries: Low Angle Twist and Asymmetric Tilt BoundariesErman Guleryuz0Sinisa Dj. Mesarovic1National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USASchool of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164, USAWe investigate the mechanisms of incipient plasticity at low angle twist and asymmetric tilt boundaries in fcc metals. To observe plasticity of grain boundaries independently of the bulk plasticity, we simulate nanoindentation of bicrystals. On the low angle twist boundaries, the intrinsic grain boundary (GB) dislocation network deforms under load until a dislocation segment compatible with glide on a lattice slip plane is created. The half loops are then emitted into the bulk of the crystal. Asymmetric twist boundaries considered here did not produce bulk dislocations under load. Instead, the boundary with a low excess volume nucleated a mobile GB dislocation and additional GB defects. The GB sliding proceeded by motion of the mobile GB dislocation. The boundary with a high excess volume sheared elastically, while bulk-nucleated dislocations produced plastic relaxation.http://www.mdpi.com/2073-4352/6/7/77intrinsic dislocationspartial dislocationsmolecular dynamicsnanoindentation |
| spellingShingle | Erman Guleryuz Sinisa Dj. Mesarovic Dislocation Nucleation on Grain Boundaries: Low Angle Twist and Asymmetric Tilt Boundaries Crystals intrinsic dislocations partial dislocations molecular dynamics nanoindentation |
| title | Dislocation Nucleation on Grain Boundaries: Low Angle Twist and Asymmetric Tilt Boundaries |
| title_full | Dislocation Nucleation on Grain Boundaries: Low Angle Twist and Asymmetric Tilt Boundaries |
| title_fullStr | Dislocation Nucleation on Grain Boundaries: Low Angle Twist and Asymmetric Tilt Boundaries |
| title_full_unstemmed | Dislocation Nucleation on Grain Boundaries: Low Angle Twist and Asymmetric Tilt Boundaries |
| title_short | Dislocation Nucleation on Grain Boundaries: Low Angle Twist and Asymmetric Tilt Boundaries |
| title_sort | dislocation nucleation on grain boundaries low angle twist and asymmetric tilt boundaries |
| topic | intrinsic dislocations partial dislocations molecular dynamics nanoindentation |
| url | http://www.mdpi.com/2073-4352/6/7/77 |
| work_keys_str_mv | AT ermanguleryuz dislocationnucleationongrainboundarieslowangletwistandasymmetrictiltboundaries AT sinisadjmesarovic dislocationnucleationongrainboundarieslowangletwistandasymmetrictiltboundaries |