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Molecular dynamics simulations of shock compression of nickel: From monocrystals to nanocrystals
- Source :
- Acta Materialia. 56:5584-5604
- Publication Year :
- 2008
- Publisher :
- Elsevier BV, 2008.
-
Abstract
- Shock compression of mono- and nanocrystalline (nc) nickel is simulated over a range of pressures (10–80 GPa) and compared with experimental results. Contributions to the strain from the various mechanisms of plastic deformation such as partial dislocations, perfect dislocations and twins are quantified in the nc samples. The effect of stress unloading, a phenomenon often neglected in MD simulations, on dislocation behavior is computed. It is shown that a large fraction of the dislocations generated during compression is annihilated upon unloading. The present analysis resolves a disagreement consistently observed between MD computations and experimental results. Analytical models are applied to predict the critical pressures for the cell-to-stacking-fault transition and the onset of twinning as a function of grain-size and stacking-fault energy (through the addition of tungsten). These predictions are successfully compared with experimental results.
- Subjects :
- Materials science
Polymers and Plastics
Metals and Alloys
Thermodynamics
chemistry.chemical_element
Tungsten
Compression (physics)
Nanocrystalline material
Electronic, Optical and Magnetic Materials
Shock (mechanics)
Stress (mechanics)
Condensed Matter::Materials Science
Crystallography
chemistry
Ceramics and Composites
Partial dislocations
Dislocation
Crystal twinning
Subjects
Details
- ISSN :
- 13596454
- Volume :
- 56
- Database :
- OpenAIRE
- Journal :
- Acta Materialia
- Accession number :
- edsair.doi...........07d08ff627ae7cd002621a7425054ee2