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Solidification of highly undercooled Sn-Pb alloy dropletsExperimental work on undercooling and structure of tin-lead droplets emulsified in oil is described. The droplets, predominantly in the size range of 10 to 20 microns, were cooled at rates (just before nucleation) ranging from about 0.1 to 1 million K/s. The higher cooling rates were obtained by a newly developed technique of quenching the emulsified droplets in a cold liquid. Measured undercoolings (at the lower cooling rates) ranged up to about 100 K. Structures obtained depend strongly on undercooling, cooling rate before and after nucleation, and alloy composition. Droplets containing up to 5 wt pct Pb were apparently single phase when undercooled and rapidly quenched. Droplets in the composition range of about 25-90 wt pct Pb solidified dendritically, even at the most rapid quench rates employed, apparently because these alloys undercooled only slightly before nucleation of the primary phase.
Document ID
19840057964
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Chu, M. G.
(Alcoa Laboratories, Alcoa Center PA, United States)
Flemings, M. C.
(MIT Cambridge, MA, United States)
Shiohara, Y.
(Aluminum Co. of America Alcoa Center, PA, United States)
Date Acquired
August 12, 2013
Publication Date
July 1, 1984
Publication Information
Publication: Metallurgical Transactions A - Physical Metallurgy and Materials Science
Volume: 15A
ISSN: 0360-2133
Subject Category
Metallic Materials
Accession Number
84A40751
Funding Number(s)
CONTRACT_GRANT: NSG-7645
Distribution Limits
Public
Copyright
Other

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