Evolution of ice crystal microstructure during creep experiments

Results of laboratory uniaxial compression tests over the stress range 0.18–0.52 MPa and the strain range 0.5–8.6% at approximately –5 and –20°C are presented. Grain-size analysis and comparisons with annealing tests confirm that grain-growth reducing processes are active during deformation. Microst...

Full description

Saved in:
Bibliographic Details
Published inJournal of glaciology Vol. 53; no. 182; pp. 479 - 489
Main Authors Hamann, Ilka, Weikusat, Christian, Azuma, Nobuhiko, Kipfstuhl, Sepp
Format Journal Article
LanguageEnglish
Published Cambridge, UK Cambridge University Press 2007
International Glaciological Society
Subjects
Earth, ocean, space
Exact sciences and technology
External geophysics
Snow. Ice. Glaciers
Polycrystalline ice
glaciology
ice sheets
textures
creep
microstructures
Property structure relationship
uniaxial compression
Strain hardening
mechanical properties
Online AccessGet full text

Cover

More Information
Summary:Results of laboratory uniaxial compression tests over the stress range 0.18–0.52 MPa and the strain range 0.5–8.6% at approximately –5 and –20°C are presented. Grain-size analysis and comparisons with annealing tests confirm that grain-growth reducing processes are active during deformation. Microstructural observations reveal that subgrain-rotation recrystallization and grain-shape changes due to strain-induced grain-boundary migration are the causes of the grain-growth deceleration. Further results from microstructural observations show that obstacle formation by dislocation walls and subgrain boundaries is the reason for isotropic hardening during creep. Subgrainboundary types that are likely to be relevant for studies on the activity of different dislocation types are described.
ISSN:0022-1430
1727-5652
DOI:10.3189/002214307783258341