一方向凝固したGaSb-CrSb共晶合金の組織
1986 年 50 巻 7 号 p. 666-670
詳細
1986 年 50 巻 7 号 p. 666-670
A eutectic alloy of GaSb-CrSb has been unidirectionally solidified at various rates of solidification, in order to investigate the structural change with the solidification condition.
The results are as follows:
(1) The spacing λ of CrSb rods was expressed to be linear to R−1⁄2, where R was the rate of solidification, and λ2R was 1.52×10−16 m3/s.
(2) The alloy specimens consisted of polycrystalline columnar grains which elongated to the solidification direction. The crystallographic orientation relationship between the GaSb and CrSb phases was determined by X-ray diffraction. A preferred relationships were observed can be stated approximately as follows:
Growth direction: ⟨110⟩GaSb\varparallel⟨0001⟩CrSb.
Crystallographic plane: {110}GaSb\varparallel{10\bar10} or {11\bar20}CrSb.
(3) The interfacial energies between the GaSb and CrSb phases was determined from a dislocation model considering the mismatch at the interface to be equal to 1.06-1.66 J/m2. Assuming that the crystal growth followed Jackson’s model, and also using this phase boundary energy, the diffusion coefficient of CrSb in molten GaSb-CrSb eutictic alloy was evaluated as D=1.6×10−9 m2/s.
