NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Phase-field model for isothermal phase transitions in binary alloysA new phase field model is described which models isothermal phase transitions between ideal binary alloy solution phases. Equations are developed for the temporal and spatial variation of the phase field, which describes the identity of the phase, and of the composition. An asymptotic analysis, as the gradient energy coefficient of the phase field becomes small, was conducted. From the analysis, it is shown that the model recovers classical sharp interface models of this situation when the interfacial layers are thin, and they show how to relate the parameters appearing in the phase field model to material and growth parameters in real systems. Further, three stages of temporal evolution are identified: the first corresponding to interfacial genesis which occurs very rapidly; the second to interfacial motion controlled by the local energy difference across the interface and diffusion; the last taking place on a long time scale in which curvature effects are important and which correspond to Ostwald ripening. The results of the numerical calculations are presented.
Document ID
19920055717
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Wheeler, A. A.
(NASA Headquarters Washington, DC United States)
Boettinger, W. J.
(NASA Headquarters Washington, DC United States)
Mcfadden, G. B.
(NIST Gaithersburg, MD, United States)
Date Acquired
August 15, 2013
Publication Date
May 15, 1992
Publication Information
Publication: Physical Review A
Volume: 45
Issue: 10, M
ISSN: 1050-2947
Subject Category
Thermodynamics And Statistical Physics
Accession Number
92A38341
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available