Result and discussion
3.1. Crystal growth
Eutectic crystals were grown at various growth speeds in an
attempt to generate rod-like microstructure. An photograph of
the grown eutectic is shown in Fig. 3a. White rod with
3 mm in diameter and 13 mm in length was obtained. BEI of
grown crystals in vertical and transverse cross-section are
shown in Fig. 3b and c. Rod phases with around 3–4 lm diameter
were observed on the transverse cross-section. Fiber-like
structure with around 100–150 lm length was observed on
the vertical cross-section along the growth direction as shown
in Fig. 3c. The result of powder XRD of the grown eutectic was
shown in Fig. 4. The grown eutectic showed two phases of
SHO and SAO. The results of powder XRD and EPMA indicated
that the white rod phase was SHO and black matrix phase was