Investigation on the leading phase of Al 2 O 3 /YAG eutectic crystals prepared by directional solidification

The leading phase of eutectic materials has an effect on the solidification behavior and further influences on their properties. Many studies have been carried out on the leading phase of metal/metal and nonmetal/metal eutectic alloys. Nevertheless, few studies were focused on no‐metal/no‐metal eutectic materials. In the present work, the leading phase in the Al2O3/Y3Al5O12 eutectic crystal during solidification was investigated by electron back‐scattered diffraction and discussed according to the classical solidification theory. It is observed that the Y3Al5O12 was the leading phase. The leading phase was determined by the wetting angle and the undercooling. At a given wetting angle, the Y3Al5O12 would be the leading phase when the undercooling exceeds the critical value.