Publication Date:
2021-03-29
Description:
Static (or ‘normal’) grain growth, i.e. grain boundary migration driven solely by grain
boundary energy, is considered to be an important process in polar ice. Many ice-core studies report a
continual increase in average grain size with depth in the upper hundreds of metres of ice sheets, while
at deeper levels grain size appears to reach a steady state as a consequence of a balance between grain
growth and grain-size reduction by dynamic recrystallization. The growth factor k in the normal grain
growth law is important for any process where grain growth plays a role, and it is normally assumed to
be a temperature-dependent material property. Here we show, using numerical simulations with the
program Elle, that the factor k also incorporates the effect of the microstructure on grain growth. For
example, a change in grain-size distribution from normal to log-normal in a thin section is found to
correspond to an increase in k by a factor of 3.5.
Keywords:
grain; growth; grain size; reduction; polar; ice
;
551
Language:
English
Type:
article
,
publishedVersion
Format:
7
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