701. Nanoscale rotational deformation near crack tips in nanocrystalline solids.
- Author
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Ovid'ko, I. A. and Sheinerman, A. G.
- Subjects
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NANOCRYSTAL synthesis , *OPTICAL properties of nanostructured materials , *AGGLOMERATES (Chemistry) , *POLYCRYSTALS , *STRESS intensity factors (Fracture mechanics) - Abstract
A special physical micromechanism of plastic flow in pre-cracked nanocrystalline solids is suggested and theoretically described. The micromechanism represents the fast nanoscale rotational deformation (NRD) occurring through collective events of ideal nanoscale shear near crack tips. We calculated the stress and energy characteristics of the NRD. It has been found that such rotational deformation can effectively occur near crack tips and enhance fracture toughness of nanocrystalline materials. Our theoretical model accounts for the in situ experimental observations (Ke et al 1995 Nanostruct. Mater.5 689, Shan et al 2008 Phys. Rev. Lett.100 105502, Cheng et al 2010 Phys. Rev. Lett.104 255501, Liu et al 2011 Scripta Mater.64 343) of crystal lattice rotations within nanoscale grains and formation of modulated/agglomerated grain structures near crack tips in deformed nanocrystalline solids with finest grains. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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