The isothermal dendritic growth experiment: Implications for theory

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:227795

Glicksman, M E; Koss, M B; Bushnell, L T; LaCombe, J C ^[1]

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1. Rensselaer Polytechnic Inst., Troy, NY (United States). Materials Engineering Dept.

The Isothermal Dendritic Growth Experiment (IDGE) is an orbital space flight experiment, launched by NASA, in March, 1994 as part of the US Microgravity Payload (USMP-2). The IDGE provided accurately measured dendritic growth rates, tip radii of curvature, and morphological observations of ultra-pure succinonitrile--all obtained at supercoolings in the range 0.05--2.0 K. Data were received in the form of pairs of digitized binary images telemetered to the ground from orbit in near-real-time, and as 35mm photographic film. The data taken above ca. 0.4 K supercooling provide the first comprehensive assessment of diffusion-limited dendritic growth, and those taken below this value yield new insights into the influence of convection. The IDGE also demonstrated that prior terrestrial dendritic growth data were generally corrupted by melt convection, making their comparison with diffusion-limited theories questionable. The new results suggest that dendritic growth in succinonitrile occurs as a diffuso-capillary phenomenon, in which the interfacial mobility in neither limited by molecular attachment or interfacial reactions.

• OSTI ID: 227795
• Report Number(s): CONF-9509118--; ISBN 0-87339-297-3
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CONVECTION
CRYSTAL GROWTH
DIFFUSION
HEAT TRANSFER
INTERFACES
KINETICS
MICROSTRUCTURE
MORPHOLOGY
NITRILES
SOLIDIFICATION
SPACE SHUTTLES
SUCCINIC ACID
VELOCITY