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Pattern selection in solidificationDirectional solidification of alloys produces a wide variety of cellular or lamellar structures which, depending upon growth conditions, may be reproducibly regular or may behave chaotically. It is not well understood how these patterns are selected and controlled or even whether there ever exist sharp selection mechanisms. A related phenomenon is the spatial propagation of a pattern into a system which has been caused to become unstable against pattern-forming deformations. This phenomenon has some features in common with the propagation of sidebranching modes in dendritic solidification. In a class of one-dimensional models, the nonlinear system can be shown to select the propagating mode in which the leading edge of the pattern is just marginally stable. This stability principle, when applicable, predicts both the speed of propagation and the geometrical characteristics of the pattern which forms behind the moving front. A boundary-layer model for fully two or three dimensional solidification problems appears to exhibit similar mathematical behavior.
Document ID
19840053249
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Langer, J. S.
(California, University Santa Barbara, CA, United States)
Date Acquired
August 12, 2013
Publication Date
June 1, 1984
Publication Information
Publication: Metallurgical Transactions A - Physical Metallurgy and Materials Science
Volume: 15A
ISSN: 0360-2133
Subject Category
Metallic Materials
Accession Number
84A36036
Funding Number(s)
CONTRACT_GRANT: DE-AM03-76SF-00034
CONTRACT_GRANT: NSF PHY-77-27084
Distribution Limits
Public
Copyright
Other

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