一方向凝固によるInSb-NiSb共晶合金の組織

Abstract

A eutectic alloy of InSb-NiSb has been unidirectionally solidified at various rates of solidification in order to investigate the structure change due to solidification condition.The results obtained are as follows:(1) The alloy specimens consisted of polycrystalline columnar grains which elongated to the solidification direction. The InSb matrix phase was oriented in the 〈110〉 direction to the growth direction. Rods of NiSb were aligned parallel to each other to the growth direction and oriented in the 〈0001〉 direction. The size of the rods was 10∼500 μ in length and 0.5∼5 μ in diameter, decreasing with increasing solidification velocity.(2) The crystallographic orientation relationship between the InSb and NiSb phases was determined by X-ray diffraction. A preferred relationship observed may be roughly stated approximately:(This article is not displayable. Please see full text pdf.) (3) The spacing between the NiSb rods was expressed to be linear to the rate of solidification R, and λ2R was 1.57×10−10 cm3/sec. Assuming that the crystal growth followed Jackson’s model, the diffusion coefficient obtained was D=3.85×10−8∼5.78×10−8 cm2/sec at the supercooling temperatures between 14° and 21°C.(4) The relative resistance RB⁄R0 of field plates made of the alloy was measured as a function of the magnetic induction. The resistance increased by a factor of 16 in a field of 10 kG.