In Situ Electron Microscopy : Solidification of Eutectic Alloys.

Abstract

A heating stage and an advanced video recording system were used in the 1 MeV electron microscope of CEN Grenoble. This allowed us to observe various aspects of eutectic solidification. These observations include regular lamellar solidification with faceted or non faceted solid-liquid interfaces, change of lamellar spacing with solidification rate, non reciprocal heterogeneous nucleation of eutectic solidification.We discuss them with respect to the classical theories and introduce a new eutectic nucleation mechanism based on surface dendrites.