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Directional Solidification of Bi-Sn on USMP-4The experiments used MEPHISTO hardware to study the solidification and melting behavior of bismuth alloyed with 1 at% tin. Three samples, each approximately 900 mm long and 6mm in diameter, were used. A portion of each sample also included a 2 mm diameter growth capillary, to assist in the formation of a single grain. One sample provided the Seebeck voltage generated during melting and freezing processes. Another provided temperature data and Peltier pulsed demarcation of the interface shape for post flight analysis. The third sample provided resistance and growth velocity measurements, as well as additional thermal data. The third sample was also quenched at the end of the mission to preserve the composition of the liquid near the interface for post flight determination. A total of 450mm of directionally solidified samples were preserved for post mission structural and compositional characterization. Substantial differences were observed in the Seebeck signal between the ground-based experiments and the space-based experiments. The temperature gradient in the liquid for the ground-based experiments was significantly lower than the temperature gradient in the liquid for the space-based experiments.
Document ID
20000030724
Acquisition Source
Legacy CDMS
Document Type
Preprint (Draft being sent to journal)
Authors
Abbaschian, Reza
(Florida Univ. Gainesville, FL United States)
deGroh, H., III
(NASA Lewis Research Center Cleveland, OH United States)
Leonardi, E.
(NASA Lewis Research Center Cleveland, OH United States)
Timchenko, V.
(NASA Lewis Research Center Cleveland, OH United States)
deVahlDavis, G.
(New South Wales Univ. Sydney, Australia)
Date Acquired
September 7, 2013
Publication Date
January 1, 1999
Subject Category
Metals And Metallic Materials
Meeting Information
Meeting: Solidification and Gravity
Country: Hungary
Start Date: April 1, 1999
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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