一方向凝固したInSb-Sb共晶合金の組織

抄録

A eutectic alloy of InSb-Sb has been unidirectionally solidified at various rates of solidification, in order to investigate the structural change with the solidification condition.
The results as follows:
(1) The spacing λ of Sb rods was expressed to be linear to R^−1⁄2, where R was the rate of solidification, and λ²R was 2.4×10⁻¹⁶ m³/s.
(2) The alloy specimens consisted of polycrystalline columnar grains which elongated to the solidification direction. The crystallographic orientation relationship between the InSb and Sb phases was determined by X-ray diffraction. A preferred relationship were observed can be stated approximately as follows:
Growth direction: ⟨110⟩InSb\varparallel⟨0001⟩, ⟨4 8 ‾12 1⟩ or ⟨24\bar6\bar1⟩Sb.
Crystallographic plane: {110} or {111}InSb\varparallel{11\bar20}, {01\bar14} or {01\bar1\bar8}Sb.
(3) The interfacial energies between the InSb and Sb phases were calculated from a dislocation model considering the mismatch at the interface to be equal to 1.25-1.88 J/m². According to the value of interfacial energy and the microscopic observation, it seems that the side direction of Sb triangles is parallel to ⟨10\bar10⟩Sb.
(4) Assuming that the crystal growth follows Jackson’s model, and also using the above-mentioned phase boundary energy, the diffusion coefficient of Sb in molten InSb-Sb eutectic alloy was evaluated as D=1.6×10⁻⁹ m²/s.