Eur. Phys. J. B 37, 85-89 (2004)
https://doi.org/10.1140/epjb/e2004-00032-2

Morphological instability induced by the interaction of a particle with a solid-liquid interface

Mathematics Department, The University of Alabama Tuscaloosa, Alabama 35487-0350, USA

Corresponding author: ^a lhadji@bama.ua.edu

Received: 20 October 2003
Revised: 3 December 2003
Published online: 19 February 2004

Abstract

We show that the interaction of a particle with a directionally solidified interface induces the onset of morphological instability provided that the particle-interface distance falls below a critical value. This instability occurs at pulling velocities that are below the threshold for the onset of the Mullins-Sekerka instability. The expression for the critical distance reveals that this instability is manifested only for certain combinations of the physical and processing parameters. Its occurence is attributed to the reversal of the thermal gradient in the melt ahead of the interface and behind the particle.