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| Titel |
Experimental investigation of structures and rheology on halite single-crystals: In-situ approach. |
| VerfasserIn |
D. Picard, A. Dimanov, J. Raphanel |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250060254
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| Zusammenfassung |
| Intracrystalline plasticity, coupled with the rheological properties, are key parameters to
constrain the flow behavior of rock salt. Crystal plasticity is inherently anisotropic and
therefore polycrystalline materials always exhibit heterogeneous behavior which results from
local scale incompatibility and involves additional accommodation mechanisms
(micro-cracking, grain sliding-¦). It is thus important to understand the interaction between
neighboring grains and inside single crystals. For this reason, we investigate crystal plasticity
of halite single-crystals (NaCl) with compression experiments performed inside a scanning
electron microscope (SEM).
Starting materials consist of high purity halite single crystals of approximately
5x5x10mm. Micro droplets of gold are deposited on the polished sample surface in order to
provide very fine markers for the Digital Image Correlation (DIC) technique used to evaluate
the surface displacement field at several steps of the loading process. The DIC method allows
to compute the strain field and to evaluate quantitatively the heterogeneity of the local
deformation which can be related to local mechanisms such as intracrystalline slip.
Compression experiments were performed along {001} using an uniaxial press installed
inside a SEM. Tests were performed at room temperature, a strain rate 9.4x10-5Â s-1 Â 5%. Moreover, from one step
to another, the deformation accommodated by a slip band can vary from 1% to
10%.
These preliminary results indicate that, even with simple loading tests and easy slip
systems, important heterogeneity of deformation occurs. Further experiments at
higher temperature and with different loading orientation will also be presented. |
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