Cellular spacings - II. Dynamical studies

Journal Article · Fri Apr 01 04:00:00 EST 1988 · Acta Metall.; (United States)

DOI:https://doi.org/10.1016/0001-6160(88)90170-8· OSTI ID:7002867

Seetharaman, V; Eshelman, M A; Trivedi, R

Directional solidification experiments were carried out in model transparent systems to establish the dynamical processes by which an unstable planar interface restabilizes into a periodic array of cells. In the succinonitrile-acetone system, where the interface properties are nearly isotropic, the cells increase their spacings by the cell elimination process and decrease their spacings by the tip-splitting mechanism. In the pivalic acid-ethanol system, the significantly anisotropic interface properties do not allow the tip-splitting phenomenon to occur readily. Dynamical studies of the variation in cellular spacing with change in growth rate show that the spacing does not alter until a significantly large change in growth rate is imposed. When a decrease in spacing occurs, two different configurations are observed depending on whether the perturbation which leads to the change is localized or nonlocalized. In the case of a localized perturbation, a propagating tip-splitting mode is observed. For nonlocalized perturbations, the entire interface undergoes a cell-planar-cell transition.

• Research Organization: Ames Lab. - USDOE and the Dept. of Materials Science and Engineering, Iowa State Univ., Ames, IA (US)
• OSTI ID: 7002867
• Journal Information: Acta Metall.; (United States), Journal Name: Acta Metall.; (United States) Vol. 36:4; ISSN AMETA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
ANISOTROPY
BIOLOGICAL EVOLUTION
CELL PROLIFERATION
CELL TRANSFORMATIONS
CLEAVAGE
CRYSTAL STRUCTURE
DATA
DYNAMIC FUNCTION STUDIES
EXPERIMENTAL DATA
INFORMATION
MICROSTRUCTURE
NUMERICAL DATA
PERTURBATION THEORY