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Directional solidification of Cu-Pb and Bi-Ga monotectic alloys under normal gravity and during parabolic flightCu-Pb and Bi-Ga monotectic alloys of nominal hypermonotectic compositions were directionally solidified under various furnace translation rates, temperature gradients, and gravity levels. Gravity was varied by solidifying the alloys under ground conditions and in the furnace aboard NASA KC-135 aircraft, flying on parabolic trajectories. High translation rates, high gradients, high gravity levels, and higher density and lower thermal conductivity of the L2 phase favored the formation of fiber composite structure, while the opposite conditions resulted in structures consisting of L2 droplets in alpha matrix. A modified particle engulfment theory as originally enunciated by Ulhmann et al. (1964) is proposed to explain these observations.
Document ID
19890029747
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Dhindaw, B. K.
(Alabama Univ. Tuscaloosa, AL, United States)
Stefanescu, D. M.
(Alabama, University Tuscaloosa, United States)
Singh, A. K.
(Inland Steel Co. East Chicago, IN, United States)
Curreri, P. A.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
August 14, 2013
Publication Date
November 1, 1988
Publication Information
Publication: Metallurgical Transactions A - Physical Metallurgy and Materials Science
Volume: 19A
ISSN: 0360-2133
Subject Category
Materials Processing
Accession Number
89A17118
Funding Number(s)
CONTRACT_GRANT: NAS8-36193
Distribution Limits
Public
Copyright
Other

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