Modelling Grain Coarsening in the Framework of Rational Extended Thermodynamics
L. Kertsch, D. Helm,
Volume: 16. Pages: 453--454
DOI: 10.1002/pamm.201610215
Published: 2016
Abstract
Grain growth and shrinkage at elevated temperatures is a significant
phenomenon during the processing of metals. Often, grain coarsening
is described without thermodynamic considerations. But since the
grain boundary mobility is thermally activated and energy stored
in the grain boundaries is released during their motion, a thermodynamic
framework is required to capture the various effects of the process.
For this purpose, the procedure of Rational Extended Thermodynamics
is applied to derive a thermodynamically consistent model for grain
coarsening due to the growth and shrinkage of individual grains.
Despite the different approach used, a grain growth model is obtained
which is similar to existing ones and can be regarded as a thermodynamic
extension of that by Hillert (1965) to more general systems. The
model reproduces grain growth experiments in pure copper very accurately
and predicts the associated energy release. The present approach
combining a microstructure description and continuum mechanics can
be further used to develop thermomechanical material models considering
the microstructure. (© 2016 Wiley-VCH Verlag GmbH \& Co. KGaA, Weinheim)