Back to Search Start Over

The influence of strain rate and presence of dispersed second phases on the deformation behaviour of polycrystalline D2O ice

Authors :
CHRISTOPHER J.L. WILSON
NICHOLAS J. R. HUNTER
VLADIMIR LUZIN
MARK PETERNELL
SANDRA PIAZOLO
Source :
Journal of Glaciology, Vol 65, Pp 101-122 (2019)
Publication Year :
2019
Publisher :
Cambridge University Press, 2019.

Abstract

This contribution discusses results obtained from 3-D neutron diffraction and 2-D fabric analyser in situ deformation experiments on laboratory-prepared polycrystalline deuterated ice and ice containing a second phase. The two-phase samples used in the experiments are composed of an ice matrix with (1) air bubbles, (2) rigid, rhombohedral-shaped calcite and (3) rheologically soft, platy graphite. Samples were tested at 10°C below the melting point of deuterated ice at ambient pressures, and two strain rates of 1 × 10āˆ’5 sāˆ’1 (fast) and 2.5 × 10āˆ’6 sāˆ’1 (medium). Nature and distribution of the second phase controlled the rheological behaviour of the ice by pinning grain boundary migration. Peak stresses increased with the presence of second-phase particles and during fast strain rate cycles. Ice-only samples exhibit well-developed crystallographic preferred orientations (CPOs) and dynamically recrystallized microstructures, typifying deformation via dislocation creep, where the CPO intensity is influenced in part by the strain rate. CPOs are accompanied by a concentration of [c]-axes in cones about the compression axis, coinciding with increasing activity of prismatic- slip activity. Ice with second phases, deformed in a relatively slower strain rate regime, exhibit greater grain boundary migration and stronger CPO intensities than samples deformed at higher strain rates or strain rate cycles.

Details

Language :
English
ISSN :
00221430 and 17275652
Volume :
65
Database :
Directory of Open Access Journals
Journal :
Journal of Glaciology
Publication Type :
Academic Journal
Accession number :
edsdoj.19a34a989e0048958602d063aacc2c8c
Document Type :
article
Full Text :
https://doi.org/10.1017/jog.2018.100