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Dendritic growth of undercooled nickel-tin. I, IIA comparison is made between high speed cinematography and optical temperature measurements of the solidification of an undercooled Ni-25 wt pct Sn alloy. The first part of this study notes that solidification during the recalescence period at all undercoolings studied occurred in the form of a dendritelike front moving across the sample surface, and that the growth velocities observed agree with calculation results for the dendrite growth model of Lipton et al. (1986); it is concluded that the coarse structure observed comprises an array of much finer, solute-controlled dendrites. In the second part, attention is given to the solidification of levitated metal samples within a transparent glass medium for the cases of two undercooled Ni-Sn alloys, one of which is eutectic and another hypoeutectic. The data obtained suggest a solidification model involving dendrites of very fine structure growing into the melt at temperatures near the bulk undercooling temperature.
Document ID
19870053738
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Wu, Y.
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Piccone, T. J.
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Shiohara, Y.
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Flemings, M. C.
(MIT Cambridge, MA, United States)
Date Acquired
August 13, 2013
Publication Date
May 1, 1987
Publication Information
Publication: Metallurgical Transactions A - Physical Metallurgy and Materials Science
Volume: 18A
ISSN: 0360-2133
Subject Category
Metallic Materials
Accession Number
87A41012
Funding Number(s)
CONTRACT_GRANT: NAG3-597
CONTRACT_GRANT: NSG-7645
Distribution Limits
Public
Copyright
Other

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