| Sb-InSb eutectic alloys containing 26∼34 wt%In were unidirectionally solidified at a temperature gradient of 57℃ and in the range of growth rate 1.2 × 10^(-4)∼1.2 × 10^(-1)㎝/s in order to investigate the coupled region and halo formation. A symmetric coupled region, widened remarkably in the range of lower growth rates, was obtained in the present f-f type eutectic system. The area fraction of primary phase increased gradually with an increase of growth rate upto 1.2 × 10^(-1)㎝/s, but it decreased considerably by quenching, implying a widening of the coupled region in the range of growth rates corresponding to quenching. Halo formation was observed around both Sb and InSb primary phases. Halo fraction was independent of alloy composition, and its dependence on the growth rate revealed the same trend as in the primary phase fraction. |
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