Microstructure evolution of Al2O3/Y3Al5O12 eutectic crystal during directional solidification

The single crystal of Al2O3/Y3Al5O12 eutectic was prepared by an optical floating zone furnace. The microstructure evolution during directional solidification was studied by electron backscattered diffraction, and orientation relationship of the two phases in SX was characterized by high resolution electron microscopy. Competitive growth of the Al2O3/Y3Al5O12 grains was observed. Single crystal Al2O3 was obtained in a shorter growth distance than Y3Al5O12 during solidification. The competitive growth behavior was discussed and misfit between the two phases was calculated.