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Containerless Liquid to Solid Nucleation Pathways in Two Representative Grades of Commercially Available ZirconiumExperimental measurements were conducted to determine the solid metal nucleation pathways of radiatively cooling, molten zirconium spheres of two different commercially available purity grades in a high-vacuum, high-temperature electrostatic levitator. The ensemble distribution of maximum undercooling temperatures was interpreted using Poisson statistics to determine the temperature dependence of the solid metal nucleation rate. For a sample of nominally 99.95% pure zirconium, the results are consistent with heterogeneous solid metal nucleation either on static catalyst particles at least approx. 30 nm diameter or on a surface coating. For a sample of nominally 99% pure zirconium, however, it appears that heterogeneous solid metal nucleation occurred either on a polydispersion of approx. 10 nm (mean diameter) static catalyst particles or on dynamic catalyst particles that precipitated from a solution that became supersaturated as the melt cooled.
Document ID
19990008464
Acquisition Source
Marshall Space Flight Center
Document Type
Reprint (Version printed in journal)
Authors
Rulison, A. J.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
Rhim, W.-K.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
Bayuzick, R.
(Vanderbilt Univ. Nashville, TN United States)
Hofmeister, W.
(Vanderbilt Univ. Nashville, TN United States)
Morton, C.
(Vanderbilt Univ. Nashville, TN United States)
Date Acquired
August 19, 2013
Publication Date
January 1, 1997
Publication Information
Publication: Acta Mater.
Publisher: Elsevier Science Publishers Ltd.
Volume: 45
Issue: 3
ISSN: 1359-6454
Subject Category
Metallic Materials
Funding Number(s)
CONTRACT_GRANT: NAG8-978
Distribution Limits
Public
Copyright
Other

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