Morphology and topology in coarsening of domains via non-conserved and conserved dynamics

Abstract

We investigate the late-stage coarsening of three-dimensional two-phase structures using non-conserved and conserved dynamics. Mixtures with a volume fraction of a phase of 50% are studied for non-conserved and conserved dynamics, and systems with volume fractions of 22%, 30%, 36%, and 40% are studied for conserved dynamics. The morphology and topology are quantified using the interfacial shape distribution and the genus, respectively. For systems with 50% volume fraction evolving via both dynamics and 36% and 40% mixtures evolving via conserved dynamics, we find that domains are bicontinuous and have time-invariant scaled morphologies and topologies. Each bicontinuous mixture yields a unique scaled interfacial shape distribution. However, all these mixtures have similar scaled topologies, yielding similar values (0.134 ± 0.004) in the scaled genus density. Additionally, these bicontinuous mixtures are different from the topology of Schoen's G surface that has been considered previously as a good model for such bicontinuous mixtures. For volume fractions of 22% and 30%, the mixtures are not bicontinuous.

Keywords:

• phase boundaries
• phase decomposition
• phase transformations

Acknowledgements

This work was supported by the National Aeronautics and Space Administration, and the Office of Naval Research and DARPA as part of the Dynamic 3-D Digital Structure Program. KT acknowledges financial support from the DOE under Grant No. DE-FG02-05ER46191.