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| Titel |
Identification of wavelengths of strain heterogeneities during creep deformation in Carrara Marble |
| VerfasserIn |
Alejandra Quintanilla-Terminel, Brian Evans |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250092733
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| Publikation (Nr.) |
 EGU/EGU2014-7092.pdf |
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| Zusammenfassung |
| We use a new technique combining microfabrication technology and compression tests to
map the strain field at a micrometric scale in polycrystalline materials. The motivation of
such high-resolution mapping is to identify characteristic wavelengths of heterogeneities for
different plasticity mechanisms under varying creep conditions. The micro-strain mapping
technique was applied to Carrara Marble under different deformation regimes, at a confining
pressure of 300 MPa and temperatures ranging from 200 to 700 °C. In samples
deformed to 10% strain in compression at 400°C, 500°C and 600°C, at a 3x10-5 s-1
strain rate, strain can be up to 5 times greater along twins and grain boundaries
compared to the macroscopic strain accommodated over the entire sample. Strain
averaged across a particular grain may vary by as much as 100%. Moreover, there is
a gradual but clear change in the accommodation of strain, from twins to grain
boundaries as temperature increases. For a fixed temperature of 600°C, varying strain
from 10% to 30% does not appear to increase the wavelength of heterogeneities
(i.e. the strain field does not homogenize). Macroscopically, strain hardening is
minimal and there seems to be a constant generation of perturbations of similar
wavelength. |
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