Results 231 to 240 of about 267,967 (278)

Directional solidification with ACRT

Journal of Crystal Growth, 1993
Abstract The interfacial mass transfer rate between the endwall and the bulk liquid in a vertical Bridgman configuration was measured during spin-up and spin-down (ACRT). The enhancement of mass transfer rate caused by spin-up and spin-down persisted much longer than the Ekman time after an impulsive change of the ampoule rotation rate.
J. Zhou, M. Larrousse, W.R. Wilcox, L.L. Regel   +3 more
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Microfaceting in directional solidification

Solid State Communications, 1994
Abstract When a thick impurity atom, like Sr, sticks to the solidification front, the latter tends to acquire a sawtooth profile in order to optimally accomodate the adsorbed monolayer. The effect is briefly described on thermodynamic and crystallographic grounds.
D. Camel, M. Papoular
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Asymmetric cell in directional solidification

Physical Review E, 1993
An asymmetric cell is obtained numerically in the symmetric model of directional solidification. It bifurcates off the symmetric cell branch and has a zero transversal velocity. The bifurcation point is characterized by a parity breaking and a period doubling. The bifurcation diagram around the codimension-two point found in previous work [Phys. Rev. A
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Parametric control of microstructures in directional solidification

Physical Review A, 1992
We consider the effect of a periodic oscillation on the growth velocity of a liquid-solid interface during the directional solidification of a binary mixture. By using a different formalism for the description of the interface motion, we confirm the eventual stabilizing properties of the oscillation found in the analysis of Wheeler (J. Cryst. Growth 67,
, Pelce, , Rochwerger
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Directional solidification of the LiF - LiBaF3 eutectic

Materials Research Bulletin, 1988
Abstract The lamellar eutectic LiF - LiBaF 3 has been directionally solidified in different furnaces and special designed cartridges with growth rates between 3 and 60 mm/h and temperature gradients from 1.5 to 7°C/mm. The growth rates have been calculated from temperature measurements in the melt.
K. Recker, F. Wallrafen, K. Dupr�
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Testing shape selection in directional solidification

Physical Review B, 1987
We report results from an experiment on the directional solidification of pivalic acid. In addition to the usual cellular interface patterns, we observe a new, metastable dendritic form that can be interpreted in the light of recent ideas about pattern formation.
, Bechhoefer, , Libchaber
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Linear stability of directional solidification cells

Physical Review A, 1990
We formulate the problem of finding the stability spectrum of the cellular pattern seen in directional solidification. This leads to a nonlinear eigenvalue problem for an integro-differential operator. We solve this problem numerically and compare our results to those obtained by linearizing the eigenvalue problem by employing the quasistatic ...
, Kessler, , Levine
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Shape of growth cells in directional solidification

Physical Review E, 2006
The purpose of this study is to characterize experimentally the whole shape of the growth cells displayed in directional solidification and its evolution with respect to control parameters. A library of cells is first built up from observation of directional solidification of a succinonitrile alloy in a large range of pulling velocity, cell spacing ...
Pocheau, Alain, Georgelin, Marc
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Observation of front propagation in directional solidification

Physical Review A, 1992
We describe how spatial variation in the critical pulling speed for directional solidification is induced by breaking the symmetry about the pulling direction. This spatial variation results in localized nucleation of the Mullins-Sekerka instability. After nucleation, the instability spreads via front propagation.
, Gleeson, , Finn, , Cladis
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Growth directions of microstructures in directional solidification of crystalline materials

Physical Review E, 2008
In directional solidification, as the solidification velocity increases, the growth direction of cells or dendrites rotates from the direction of the thermal gradient to that of a preferred cristalline orientation. Meanwhile, their morphology varies with important implications for microsegregation. Here, we experimentally document the growth directions
Deschamps, Julien, Georgelin, Marc, Pocheau, Alain   +2 more
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