Nagoya University

Inter-university Research Institute Corporation National Institutes of Natural Sciences

Genesis Research Institute, Incorporated

Other

Toyota Jidosha Kabushiki Kaisha

Nippon Steel Corporation

Shigeo Asai

Takunori Taira

Jun Akiyama

Kensuke Sassa

Kunihiko Hara

Eiichi Takeuchi

Takehiko Toh

Kenzo Sawada

Tingju Li

Kiyoshi Wajima

Kazuhiko Iwai

Qiang Wang

Takahisa Taniguchi

Upon producing a transparent polycrystalline material, a suspension liquid (or slurry) is prepared, the suspension liquid being made by dispersing a raw-material powder in a solution, the raw-material powder including optically anisotropic single-crystalline particles to which a rare-earth element is added. A formed body is obtained from the suspension liquid by means of carrying out slip casting in a space with a magnetic field applied. On this occasion, while doing a temperature control so that the single-crystalline particles demonstrate predetermined magnetic anisotropy, one of static magnetic fields and rotary magnetic fields is selected in compliance with a direction of an axis of easy magnetization in the single-crystalline particles, and is then applied to them. A transparent polycrystalline material is obtained by sintering the formed body, the transparent polycrystalline material having a polycrystalline structure whose crystal orientation is controlled.

Transparent polycrystalline material and production process for the same

Provided is a method for manufacturing a translucent polycrystalline material with optical properties continuously varying in the material. A slurry including single crystal grains that are acted upon by a force when placed in a magnetic field is immobilized in a gradient magnetic field with a spatially varying magnetic flux density and then sintered. For example, where a slurry including single crystal grains of YAG doped with Er and single crystal grains of YAG undoped with a rare earth material is immobilized in the gradient magnetic field, the region with a strong magnetic field becomes a laser oscillation region that is rich in Er-doped YAG, whereas the region with a weak magnetic field becomes a translucent region rich in YAG undoped with a rare earth material. A polycrystalline material having a core with laser oscillations and a guide surrounding the core are obtained at once.

Translucent polycrystalline material and manufacturing method thereof

Upon producing a transparent polycrystalline material, a suspension liquid (or slurry) is prepared, the suspension liquid being made by dispersing a raw-material powder in a solution, the raw-material powder including optically anisotropic single-crystalline particles to which a rare-earth element is added. A formed body is obtained from the suspension liquid by means of carrying out slip casting in a space with a magnetic field applied. On this occasion, while doing a temperature control so that the single-crystalline particles demonstrate predetermined magnetic anisotropy, one of static magnetic fields and rotary magnetic fields is selected in compliance with a direction of an axis of easy magnetization in the single-crystalline particles, and is then applied to them. A transparent polycrystalline material is obtained by sintering the formed body, the transparent polycrystalline material having a polycrystalline structure whose crystal orientation is controlled. In this calcination step, after subjecting the formed body to primary sintering at a temperature of 1,600-1,900 K, the resulting primarily-sintered body undergoes hot-isotropic-press sintering (or HIP processing) at a temperature of 1,600-1,900 K.

A static magnetic field and a wave are applied to an electrically conductive fluid so as to satisfy the mathematical expression&#x3c;(&#x3c3;/&#x3c1;),where f is the frequency (Hz) of the applied wave, &#x3c3; is the electrical conductivity (S/m) of the conductive fluid, &#x3c1; is the density (kg/m) of the conductive fluid, and B is the strength of the applied static magnetic field (T), to thereby generate and propagate vibratory motion into the conductive fluid.

Method for propagating vibratory motion into a conductive fluid and using the method to solidify a melted metal

An apparatus for generating compression waves in a conductive liquid comprises a vessel containing a conductive liquid and ac electromagnetic force applying means provided around the vessels for generating the compression waves to achieve improvement after solidification of the liquid by enchancing strength of the compression waves by setting the ac frequency &ldquo;f&rdquo; of ac electromagnetic force applying means only within the range defined by the expression 2/(L &pgr;&mgr;&sgr;)&lE;f&lE;(c &mgr;&sgr;)/2&pgr;, wherein f is a major frequency when a waveform of an electromagnetic force is developed by the Fourier transform, for a non-sine waveform, L is a characteristic length of the system, such as a depth or a radius of the vessel, &mgr; is the permeability of the conductive liquid, &sgr; is the electric conductivity of the conductive liquid, and c is the propagation velocity of the compression waves in the conductive liquid.

Apparatus for generating compression waves in conductive liquid

An object of the present invention is to provide a process for continuously casting a molten metal which process suppresses the instability of the initial solidification and stably improves the lubrication and the surface properties of the cast metal, and an apparatus therefore, in the process for continuously casting a molten metal an alternating current is applied to an electromagnetic coil which is provided so that it surrounds a continuous casting mold wall or is embedded in the side wall of the mold, whereby an electromagnetic force is exerted on the molten metal poured into the mold which either oscillates in a constant mode or does not oscillate and is starting to be solidified the process of the present invention also comprises periodically changing the amplitude or waveform of the alternating current to be applied, and the apparatus of the present invention is used for the process.

Apparatus for continuous casting of metal

A method for producing electro- or electroless-deposited-film, in which the crystal orientation of the film is controlled to provide improved product properties. A paramagnetic material or diamagnetic material in its electrolytic-state is deposited on a substrate by an electro- or electroless-deposition process. A magnetic field having an intensity at least on the order of 7 T is applied in a predetermined direction, so as to perform the deposition in environment added with the magnetic field. A porous plate is preferably arranged adjacent to the substrate, for suppressing flow of an electrolytic liquid that may occur during the application of the magnetic field.

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Nagoya, Japan

Shigeo Asai