Title :

On the formation mechanisms of intragranular shear bands in olivine by stress-induced amorphization

Author(s) :

Idrissi, Hosni [Auteur]
Université Catholique de Louvain = Catholic University of Louvain [UCL]
Béché, Armand [Auteur]
Electron Microscopy for Materials Science - EMAT (Antwerp, Belgium)
Gauquelin, Nicolas [Auteur]
Electron Microscopy for Materials Science - EMAT (Antwerp, Belgium)
Ul-Haq, Ihtasham [Auteur]
Electron Microscopy for Materials Science - EMAT (Antwerp, Belgium)
Bollinger, Caroline [Auteur]
Bavarian Research Institute of Experimental Geochemistry and Geophysics [Bayerisches Geoinstitut]
Demouchy, Sylvie [Auteur]
Géosciences Montpellier
Verbeeck, Johan [Auteur]
Electron Microscopy for Materials Science - EMAT (Antwerp, Belgium)
Pardoen, Thomas [Auteur]
Université Catholique de Louvain = Catholic University of Louvain [UCL]
Schryvers, Dominique [Auteur]
Electron Microscopy for Materials Science - EMAT (Antwerp, Belgium)
Cordier, Patrick [Auteur]
Unité Matériaux et Transformations (UMET) - UMR 8207

Journal title :

Acta Materialia

Volume number :

239

Pages :

118247

Publisher :

Elsevier BV

Publication date :

2022-10-05

ISSN :

1359-6454

English keyword(s) :

Stress-induced amorphization mechansims
Shear band
Olivine

HAL domain(s) :

Physique [physics]/Matière Condensée [cond-mat]/Science des matériaux [cond-mat.mtrl-sci]
Planète et Univers [physics]/Sciences de la Terre

English abstract : [en]

Intragranular amorphization shear lamellae are found in deformed olivine aggregates. The detailed transmission electron microscopy analysis of intragranular lamella arrested in the core of a grain provides novel information ...
Show more >Intragranular amorphization shear lamellae are found in deformed olivine aggregates. The detailed transmission electron microscopy analysis of intragranular lamella arrested in the core of a grain provides novel information on the amorphization mechanism. The deformation field is complex and heterogeneous, corresponding to a shear crack type instability involving mode I, II and III opening components. The formation and propagation of the amorphous lamella is accompanied by the formation of crystal defects ahead of the tip. These defects are geometrically necessary [001] dislocations, characteristics of high-stress deformation in olivine, and rotational nanodomains which are tentatively interpreted as disclinations. We show that these defects play an important role in dictating the path followed by the amorphous lamella. Stress-induced amorphization in olivine would thus result from a direct crystal-to-amorphous transformation associated with a shear instability and not from a mechanical destabilization due to the accumulation of high number of defects from an intense preliminary deformation. The preferential alignment of some lamellae along (010) is a proof of the lower ultimate mechanical strength of these planes.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Internationale

Popular science :

Non

European Project :

Rheology of Earth materials: closing the gap between TIMEscales in the laboratory and in the MANtle

Administrative institution(s) :

Université de Lille
CNRS
INRAE
ENSCL

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Research team(s) :

Plasticité

Submission date :

2022-08-16T16:08:17Z
2022-08-22T13:42:01Z