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Cellular instability in rapid directional solidification - Bifurcation theoryMerchant and Davis performed a linear stability analysis on a model for the directional solidification of a dilute binary alloy valid for all speeds. The analysis revealed that nonequilibrium segregation effects modify the Mullins and Sekerka cellular mode, whereas attachment kinetics has no effect on these cells. In this paper, the nonlinear stability of the steady cellular mode is analyzed. A Landau equation is obtained that determines the amplitude of the cells. The Landau coefficient here depends on both nonequilibrium segregation effects and attachment kinetics. This equation gives the ranges of parameters for subcritical bifurcation (jump transition) or supercritical bifurcation (smooth transition) to cells.
Document ID
19920073957
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Braun, R. J.
(NASA Headquarters Washington, DC United States)
Davis, S. H.
(Northwestern University Evanston, IL, United States)
Date Acquired
August 15, 2013
Publication Date
October 1, 1992
Publication Information
Publication: Acta Metallurgica et Materialia
Volume: 40
Issue: 10, O
ISSN: 0956-7151
Subject Category
Metallic Materials
Accession Number
92A56581
Distribution Limits
Public
Copyright
Other

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