Results 251 to 260 of about 23,384 (281)

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
openaire   +2 more sources

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
openaire   +2 more sources

Directional solidification of aluminium–copper alloys

Materials Science and Engineering: A, 2002
Abstract Directional solidification experiments have been carried out on different Al–Cu alloys as a function of solidification parameters, temperature gradient G, growth rate V, and composition C0. The specimens were solidified under steady state conditions with a constant temperature gradient (7.4 K mm−1) at a wide range of growth rates (9–490 μm s−
ÇADIRLI, Emin, Gunduz, Mehmet
openaire   +2 more sources

Direct observation of microbubbles in directional solidification of salol

Physical Review Letters, 1990
Dynamic light scattering at the crystal-melt interface of solidifying salol was followed for 14 days. The hydrodynamic radius deduced from intensity correlation data increased continuously from {approx}1 to {approx}100 {mu}m. When the scattering layer was trapped by the advancing crystal front, microscopic observation revealed bubbles as inclusions ...
, Williams, , Srinivasan, , Cummins
openaire   +2 more sources

Thermosolutal convection during directional solidification

Metallurgical Transactions A, 1984
During solidification of a binary alloy at constant velocity vertically upward, thermosolutal convection can occur if the solute rejected at the crystal-melt interface decreases the density of the melt. We assume that the crystal-melt interface remains planar and that the flow field is periodic in the horizontal direction.
G. B. McFadden, R. G. Rehm, S. R. Coriell, W. Chuck, K. A. Morrish   +4 more
openaire   +1 more source

Pattern Formation in Directional Solidification

MRS Proceedings, 2003
We simulate directional solidification using the phase field method solved with adaptive mesh refinement. We examine length scale selection for two cases. For small surface tension anisotropy directed at forty five degrees relative to the pulling direction, we observe a transition from a seaweed to dendrite morphology as the thermal gradient is lowered,
Mike Greenwood, Mikko Haataja, Nikolas Provatas   +2 more
openaire   +1 more source

Directional solidification of NiAlCrFe alloy

Scripta Materialia, 1997
During directional solidification of engineering alloys, the formation of cellular and dendritic structures with concomitant microsegregation and microporosity is of great interest since these solidification features significantly influence mechanical properties.
J. Lapin, A. Klimová, R. Velísek, M. Kursa   +3 more
openaire   +1 more source

Striation in Bridgman directional solidification

Journal of Crystal Growth, 1998
Abstract Time-dependent behaviours induced by the solutal convection appearing above a solidification front are numerically investigated. The system under study corresponds to the upward Bridgman configuration for the directional solidification of the Pb–30% Tl alloy.
R Guérin, C Le Marec, P Haldenwang
openaire   +1 more source

Convective instabilities during directional solidification

Journal of Thermophysics and Heat Transfer, 1989
Results of a ground-based experimental program that supports a low-gravity space processing Spacelab experiment are reported. The phenomena which precipitate pluming and thus freckling in a metal alloy are studied in detail using a metal analog (ammonium chloride and water) and the sequential events leading to massive channeling and convection are ...
T. D. McCay, M. H. McCay, S. A. Lowry, L. M. Smith   +3 more
openaire   +1 more source

Pattern formation in directional solidification

Physical Review B, 1983
The one-sided model for a nearly planar solidification front advancing at steady velocity is studied. The model neglects impurity diffusion in the solid; the interface is stabilized by the imposition of a thermal gradient. The front, located at ${z}_{s}={z}_{s}(x,y)$, is described by the coefficients ${\ensuremath{\epsilon}}_{\stackrel{\ensuremath ...
openaire   +1 more source