Thermodynamic phase-field model for microstructure with multiple components and phases: The possibility of metastable phases
Author(s)
Cogswell, Daniel A.; Carter, W. Craig
DownloadCogswell-2011-Thermodynamic phase-.pdf (1.152Mb)
PUBLISHER_POLICY
Publisher Policy
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Terms of use
Metadata
Show full item recordAbstract
A diffuse-interface model for microstructure with an arbitrary number of components and phases was developed from basic thermodynamic and kinetic principles and formalized within a variational framework. The model includes a composition gradient energy to capture solute trapping and is therefore suited for studying phenomena where the width of the interface plays an important role. Derivation of the inhomogeneous free energy functional from a Taylor expansion of homogeneous free energy reveals how the interfacial properties of each component and phase may be specified under a mass constraint. A diffusion potential for components was defined away from the dilute solution limit, and a multi-obstacle barrier function was used to constrain phase fractions. The model was used to simulate solidification via nucleation, premelting at phase boundaries and triple junctions, the intrinsic instability of small particles, and solutal melting resulting from differing diffusivities in solid and liquid. The shape of metastable free energy surfaces is found to play an important role in microstructure evolution and may explain why some systems premelt at phase boundaries and phase triple junctions, whereas others do not.
Date issued
2011-06Department
Massachusetts Institute of Technology. Department of Chemical Engineering; Massachusetts Institute of Technology. Department of Materials Science and EngineeringJournal
Physical Review E
Publisher
American Physical Society
Citation
Cogswell, Daniel, and W. Carter. “Thermodynamic Phase-field Model for Microstructure with Multiple Components and Phases: The Possibility of Metastable Phases.” Physical Review E 83.6 (2011) ©2011 American Physical Society
Version: Final published version
ISSN
1539-3755
1550-2376