Long-time dynamics of the directional solidification of rodlike eutectics

Mikael Perrut (1) , Silvère Akamatsu (1) , Sabine Bottin-Rousseau (1) , Gabriel Faivre (1)

1 INSP - Institut des Nanosciences de Paris

We report long-duration real-time observations of the dynamics of hexagonal (rodlike) directional-solidification patterns in bulk samples of a transparent eutectic alloy. A slight forward curvature of the isotherms induces a slow dilatation of the growth pattern at constant solidification rate and triggers the rod-splitting instability. At long times, the rod-splitting frequency exactly balances the dilatation driven by the curved isotherms. The growth pattern is then disordered and nonstationary but has a sharply selected mean spacing. Well-ordered growth patterns can be grown using time-dependent solidification rates.

Mots clés: directional solidification; eutectic alloys

Domaines: Matière Condensée [cond-mat]

Mikael Perrut, Silvère Akamatsu, Sabine Bottin-Rousseau, Gabriel Faivre. Long-time dynamics of the directional solidification of rodlike eutectics. Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, 2009, 79 (3, 1), pp.032602. ⟨10.1103/PhysRevE.79.032602⟩. ⟨hal-01239043⟩