Uniaxial compression of calcite single crystals at room temperature: insights into twinning activation and development
<p><span class="inline-formula"><i>E</i></span>-twinning is a common plastic deformation mechanism in calcite deformed at low temperature. Strain rate, temperature and confining pressure have negligible effects on twinning activation which is mainly dependent...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-02-01
|
| Series: | Solid Earth |
| Online Access: | https://www.solid-earth.net/10/307/2019/se-10-307-2019.pdf |
| _version_ | 1819013479438221312 |
|---|---|
| author | C. Parlangeau C. Parlangeau A. Dimanov O. Lacombe S. Hallais J.-M. Daniel |
| author_facet | C. Parlangeau C. Parlangeau A. Dimanov O. Lacombe S. Hallais J.-M. Daniel |
| author_sort | C. Parlangeau |
| collection | DOAJ |
| description | <p><span class="inline-formula"><i>E</i></span>-twinning is a common plastic deformation mechanism in calcite
deformed at low temperature. Strain rate, temperature and confining pressure
have negligible effects on twinning activation which is mainly dependent on
differential stress. The critical resolved shear stress (CRSS) required for
twinning activation is dependent on grain size and strain hardening. This
CRSS value may obey the Hall–Petch relation, but due to sparse experimental
data its actual evolution with grain size and strain still remains a matter
of debate.</p>
<p>In order to provide additional constraints on twinning activation and
development, new mechanical tests were carried out at room temperature on
unconfined single crystals of calcite, with different sizes and
crystallographic orientations. Uniaxial deformation was performed at a
controlled displacement rate, while the sample surface was monitored using
optical microscopy and a high-resolution CCD (charge-coupled device) camera. The retrieved macroscopic
stress–strain behavior of the crystals was correlated with the surface
observations of the deformation process.</p>
<p>Results show (1) the onset of crystal plasticity with the activation of the
first isolated mechanical twins during the strain hardening stage, and
(2) the densification and thickening of twin lamellae during the steady-state
flow stress stage. Such thickening of twin lamellae at room temperature
emphasizes that calcite twin morphology is not controlled solely by
temperature. The different values for the CRSS obtained for the activation of
isolated twins and for the onset of twin densification and thickening
raises questions regarding the appropriate value to be considered when using calcite twin data
for stress inversion purposes.</p> |
| first_indexed | 2024-12-21T02:00:36Z |
| format | Article |
| id | doaj.art-cbedcd246728493dadc7d1cca37c4b0a |
| institution | Directory Open Access Journal |
| issn | 1869-9510 1869-9529 |
| language | English |
| last_indexed | 2024-12-21T02:00:36Z |
| publishDate | 2019-02-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Solid Earth |
| spelling | doaj.art-cbedcd246728493dadc7d1cca37c4b0a2022-12-21T19:19:39ZengCopernicus PublicationsSolid Earth1869-95101869-95292019-02-011030731610.5194/se-10-307-2019Uniaxial compression of calcite single crystals at room temperature: insights into twinning activation and developmentC. Parlangeau0C. Parlangeau1A. Dimanov2O. Lacombe3S. Hallais4J.-M. Daniel5Laboratoire de Mécanique des Solides (LMS), Ecole Polytechnique, 91128 Palaiseau, FranceInstitut des Sciences de la Terre de Paris, Sorbonne Université, CNRS-INSU, ISTeP UMR 7193, 75005 Paris, FranceLaboratoire de Mécanique des Solides (LMS), Ecole Polytechnique, 91128 Palaiseau, FranceInstitut des Sciences de la Terre de Paris, Sorbonne Université, CNRS-INSU, ISTeP UMR 7193, 75005 Paris, FranceLaboratoire de Mécanique des Solides (LMS), Ecole Polytechnique, 91128 Palaiseau, FranceIFREMER, 29280 Plouzané, France<p><span class="inline-formula"><i>E</i></span>-twinning is a common plastic deformation mechanism in calcite deformed at low temperature. Strain rate, temperature and confining pressure have negligible effects on twinning activation which is mainly dependent on differential stress. The critical resolved shear stress (CRSS) required for twinning activation is dependent on grain size and strain hardening. This CRSS value may obey the Hall–Petch relation, but due to sparse experimental data its actual evolution with grain size and strain still remains a matter of debate.</p> <p>In order to provide additional constraints on twinning activation and development, new mechanical tests were carried out at room temperature on unconfined single crystals of calcite, with different sizes and crystallographic orientations. Uniaxial deformation was performed at a controlled displacement rate, while the sample surface was monitored using optical microscopy and a high-resolution CCD (charge-coupled device) camera. The retrieved macroscopic stress–strain behavior of the crystals was correlated with the surface observations of the deformation process.</p> <p>Results show (1) the onset of crystal plasticity with the activation of the first isolated mechanical twins during the strain hardening stage, and (2) the densification and thickening of twin lamellae during the steady-state flow stress stage. Such thickening of twin lamellae at room temperature emphasizes that calcite twin morphology is not controlled solely by temperature. The different values for the CRSS obtained for the activation of isolated twins and for the onset of twin densification and thickening raises questions regarding the appropriate value to be considered when using calcite twin data for stress inversion purposes.</p>https://www.solid-earth.net/10/307/2019/se-10-307-2019.pdf |
| spellingShingle | C. Parlangeau C. Parlangeau A. Dimanov O. Lacombe S. Hallais J.-M. Daniel Uniaxial compression of calcite single crystals at room temperature: insights into twinning activation and development Solid Earth |
| title | Uniaxial compression of calcite single crystals at room temperature: insights into twinning activation and development |
| title_full | Uniaxial compression of calcite single crystals at room temperature: insights into twinning activation and development |
| title_fullStr | Uniaxial compression of calcite single crystals at room temperature: insights into twinning activation and development |
| title_full_unstemmed | Uniaxial compression of calcite single crystals at room temperature: insights into twinning activation and development |
| title_short | Uniaxial compression of calcite single crystals at room temperature: insights into twinning activation and development |
| title_sort | uniaxial compression of calcite single crystals at room temperature insights into twinning activation and development |
| url | https://www.solid-earth.net/10/307/2019/se-10-307-2019.pdf |
| work_keys_str_mv | AT cparlangeau uniaxialcompressionofcalcitesinglecrystalsatroomtemperatureinsightsintotwinningactivationanddevelopment AT cparlangeau uniaxialcompressionofcalcitesinglecrystalsatroomtemperatureinsightsintotwinningactivationanddevelopment AT adimanov uniaxialcompressionofcalcitesinglecrystalsatroomtemperatureinsightsintotwinningactivationanddevelopment AT olacombe uniaxialcompressionofcalcitesinglecrystalsatroomtemperatureinsightsintotwinningactivationanddevelopment AT shallais uniaxialcompressionofcalcitesinglecrystalsatroomtemperatureinsightsintotwinningactivationanddevelopment AT jmdaniel uniaxialcompressionofcalcitesinglecrystalsatroomtemperatureinsightsintotwinningactivationanddevelopment |