Lamellar eutectic growth with anisotropic interphase boundaries: Experimental study using the rotating directional solidification method

S Akamatsu , S Bottin-Rousseau , M Sererefoğlu , G S Faivre (1)

1 INSP-E6 - Physico-chimie et dynamique des surfaces

We report on an experimental study of the effects of interphase boundary anisotropy on eutectic microstructures using a new methodology called rotating directional solidification (RDS), which consists of rotating a thin sample with respect to a fixed unidirectional thermal gradient. The systems used are thin, large eutectic grains of the CBr 4 –C 2 Cl 6 and In–In 2 Bi lamellar eutectic alloys. The shape of the observed RDS lamellar trajectories turns out to be a reproducible eutectic-grain-dependent feature, in agreement with the theoretical prediction that these trajectories are approximately homothetic to the Wulff form of the interphase boundary in the sample plane. We show that different modes of lamellar growth, ranging from quasi-isotropic to (crystallographically) locked, exist in different eutectic grains of the two alloys studied. A detailed characterisation of these modes is given, with particular attention to the as-yet poorly understood aspects of locked lamellar growth.

Mots clés: Eutectic solidification; Solidification microstructures; Interphase boundaries; Directional solidification

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Science non linéaire [physics]; Chimie

S Akamatsu, S Bottin-Rousseau, M Sererefoğlu, G S Faivre. Lamellar eutectic growth with anisotropic interphase boundaries: Experimental study using the rotating directional solidification method. Acta Materialia, 2012, 60 (6-7), pp.3206-3214. ⟨10.1016/j.actamat.2012.02.033⟩. ⟨hal-01448370⟩