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Time development of a perturbed-spherical nucleus in a pure supercooled liquid. I - Power-law growth of morphological instabilities. II - Nonlinear developmentThe linear growth stage of the morphological instabilities developing at the liquid-solid interface during crystal growth from an axisymmetric spherical nucleus is analyzed. The corresponding growth rate parameters are calculated numerically, and it is shown that morphological instabilities for free growth evolve according to a power law in agreement with WKB results and contrary to an exponential law found in a quasi-stationary approximation. The time evolution of an arbitrary perturbed liquid-solid interface from a linear into the nonlinear stage is studied. The initial perturbations include the eigenfunctions for the linear problem, localized perturbations of the grain-boundary type, and a stochastic noise. It is shown that the perturbations grow and spread in a wavelike manner. The formation of a predendritic growth stage is characterized by establishment of constant values of tip radius and velocity.
Document ID
19910031482
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Pines, V.
(NASA Lewis Research Center Cleveland, OH, United States)
Zlatkowski, M.
(NASA Lewis Research Center Cleveland, OH, United States)
Chait, A.
(NASA Lewis Research Center Cleveland, OH, United States)
Date Acquired
August 15, 2013
Publication Date
November 15, 1990
Publication Information
Publication: Physical Review A
Volume: 42
ISSN: 1050-2947
Subject Category
Solid-State Physics
Accession Number
91A16105
Distribution Limits
Public
Copyright
Other

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