Journal article
Dendrite tip growth velocities of settling NH4Cl equiaxed crystals
Scripta materialia, Vol.36(6), pp.633-638
1997
DOI: 10.1016/S1359-6462(96)00435-6
Abstract
Dendrite tip growth velocities were measured for equiaxed NH4Cl crystals settling in a supercooled aqueous solution. Data are reported as a function of the relative velocity between the crystal and the solution and several supercoolings. The tip velocities are more than two orders of magnitude higher than those in a purely diffusive environment. The data show considerable scatter, which can be attributed to orientation effects, measurement uncertainties, or other unknown influences (such as the varying overall structure of the crystals). Preliminary comparisons with the Stokes solution of Ananth and Gill (10) for a single dendrite tip growing into an approaching uniform flow show that the measured tip velocities can be approximately predicted. However, uncertainties with regard to the Gibbs-Thomson coefficient of NH4Cl are large. It can be concluded that more accurate theories are needed to predict dendrite tip growth velocities for equiaxed crystals in the presence of convection.
Details
- Title: Subtitle
- Dendrite tip growth velocities of settling NH4Cl equiaxed crystals
- Creators
- A RAMANI - Department of Mechanical Engineering, The University of Iowa, Iowa City, IA 52242, United StatesC BECKERMANN - Department of Mechanical Engineering, The University of Iowa, Iowa City, IA 52242, United States
- Resource Type
- Journal article
- Publication Details
- Scripta materialia, Vol.36(6), pp.633-638
- Publisher
- Elsevier Science; New York, NY
- DOI
- 10.1016/S1359-6462(96)00435-6
- ISSN
- 1359-6462
- eISSN
- 1872-8456
- Language
- English
- Date published
- 1997
- Academic Unit
- Mechanical Engineering
- Record Identifier
- 9984064208902771
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