Transient convective instabilities in directional solidification

Cellular instabilities in directional solidification

2014 We have studied the morphology of the solid-liquid interface during the directional solidification of thin (5-150 03BCm) samples of a dilute binary mixture (CBr4/~ 0.1 % Br2) . Above a critical pulling speed, for a given temperature gradient and solute concentration, the interface, initially planar, breaks down into a periodic cellular pattern. The bifurcation from a planar to a cellular s...

Convective instabilities during the solidification of an ideal ternary alloy in a mushy layer

DANIEL M. ANDERSON†, GEOFFREY B. McFADDEN, SAM R. CORIELL AND BRUCE T. MURRAY Department of Mathematical Sciences, George Mason University, Fairfax, VA 22030, USA Mathematical and Computational Sciences Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA Metallurgy Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA Department ...

Transient Effects in Dendritic Solidification

Dendritic solidification is a common mode of solidification. It is also an important model problem in non-equilibrium physics and pattern formation physics. Current theories couple the transfer of latent heat with selection mechanisms at the interface. Measurements of succinonitrile (SCN) dendrites in microgravity show reasonable agreement between heat transfer predictions and experiment. Howev...

Convective Instabilities in Plane Couette Flow

Onset of sidebranching in directional solidification.

We use a computationally efficient phase-field formulation [B. Echebarria, Phys. Rev. E 70, 061604 (2004)] to investigate the origin and dynamics of sidebranching in directional solidification for realistic parameters of a dilute alloy previously studied experimentally [M. Gorgelin and A. Pocheau, Phys. Rev. E 57, 3189 (1998)]. Sidebranching is found to result either from noise amplification or...