We simulate in two dimensions the cellular solidification of a binary alloy, to focus on the emergence of a secondary instability consisting in the periodic detachment of liquid droplets from the bottom of the intercellular liquid grooves. This phenomenon, observed in the solidification of thin samples, was previously interpreted in terms of an instability of the liquid-jet type; as it should occur only in three-dimensional systems, it was argued that even for thin samples the grooves have a tubelike structure. Recently the droplets detachment has been evidenced also in a two-dimensional simulation, so that a different interpretation should be given. We show that the phenomenon arises as the result of diffusional and capillary effects driven by the strong curvature of the solid-liquid interface. The dependence of the emission frequency and the droplets radius on the growth velocity is also studied.

Groove instability in cellular solidification

CONTI, Massimo;MARINI BETTOLO MARCONI, Umberto
2001-01-01

Abstract

We simulate in two dimensions the cellular solidification of a binary alloy, to focus on the emergence of a secondary instability consisting in the periodic detachment of liquid droplets from the bottom of the intercellular liquid grooves. This phenomenon, observed in the solidification of thin samples, was previously interpreted in terms of an instability of the liquid-jet type; as it should occur only in three-dimensional systems, it was argued that even for thin samples the grooves have a tubelike structure. Recently the droplets detachment has been evidenced also in a two-dimensional simulation, so that a different interpretation should be given. We show that the phenomenon arises as the result of diffusional and capillary effects driven by the strong curvature of the solid-liquid interface. The dependence of the emission frequency and the droplets radius on the growth velocity is also studied.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11581/116729
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? 0
social impact