New Development of Electromagnetic Processing of Materials

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1) By use of a super conductingmagnet, the effects of a strong magnetic field (5T) on the alignment of precipitating phase and the control of crystal orientation were studied. The intermetallic compound BiMn precipitating from Mn-4wt%Bi alloy aligns in parallel to the imposed magnetic field direction and the intermetallic compound AlSiFe precipitating from Al-11wt%Si-2wt%Fe aligns in perpendicular to the magnetic field direction. The carbon fibers in a water are oriented in parallel to the magnetic field direction. The fact that a-and b-planes align in perpendicular to the magnectic field was found in the experiment. These evidences were confirmed in the theoretical consideration.2) In order to clarify the effect of a strong magnetic field on the concentration profiel of an alloy, the uniderectional solidification of (Bi_<0.25>Sb_<0.75>) Te_3 was carried out using the vertical Bridgeman method under a strong magnetic field. The concentration of Bi in the center part is increasing along … More the grouth direction and the radial distribution of Bi is high at the center part and Bi_2Te_2 segregates there. This reason was considered from the theoretical view point.3) The effect of a magnetic field on the natural convection of an electrically conductive fluid in a cubic vessel was studied by use of a mathematical model. The model which consists of the mass, energy and momentum balances was solved all together under the assumptions of incompressible fluid and the Boussineq's approximation. From the model it is found that the heat transfer is enhanced with increase of the intensity of the magnetic field in some ranges.4) The levitation of a droplet and its stabilization due to the magnetization force was demonstrated by using a diamagnetic slicon oil droplet in a diluted magnetic fluid under a magnetic field and a mathematical model was developed. The following results were obtained.1.The diamagnetic droplet can be levitated under the coexistence of unsoluble magnetic and nonmagnetic fluids by only imposition of a weak magnetic field.2.The diamagnetic droplet which has smaller magnetic susceptibility than the surrounding medium was stabilized in the center part between poles under the magnetic field created by facing the same polarity dur to the magnetization force directing toward the center part. Less