Dowa Mining Co., Ltd.

Dowa Electronics Materials Co., Ltd.

Chubu Electric Power Company, Inc.

Dowa F-tec Co., Ltd.

Shuichi Kohayashi

Shuji Yoshizawa

Shigeo Nagaya

Shuetsu Haseyama

Naoji Kashima

Kazuyuki Uemura

Kazuya Yamaguchi

Keisuke Ayabe

Hideki Katayama

Hiroya Ikeda

Kazuyoshi Amasaki

Yoshikazu Omoto

To provide ferrite magnetic powders for bond magnet capable of surely suppressing residual hexavalent chrome, being an environmental load substance, having no adverse influence on the magnetic characteristics, which is an obstacle in use, and without damaging productivity and at a low cost. The method includes the steps of obtaining sintered powders by sintering raw material powders; wet-pulverizing the sintered powders; wet-cleaning the sintered powders; and annealing the cleaned sintered powders, wherein in the step of the wet-pulverization and in the step of wet-cleaning, generation of the hexavalent chrome, being an environmental load substance, is suppressed by performing the pulverization and cleaning while maintaining pH of a dispersion solvent at 8.5 or less, at the time of pulverization and cleaning.

Ferrite magnetic powder for bond magnet and manufacturing method of the same, and bond magnet

A metal paste, in which a filler mainly composed of metal is mixed with good dispersibility, is manufactured with good productivity at a low cost without generating a foil of the metal. A paste-like material (referred to as a paste material hereafter) containing a metal filler is fed into a gap between a pair of rotating whetstonesandwhich are relatively rotated while facing with each other having a specified gap therebetween, to pass and discharge therein. The paste material is thus kneaded and dispersed. In addition, the paste material is kneaded and dispersed by suppressing the generation of a metal foil, adjusting the gap to a specified interval dg and feeding the paste material into the interval while applying thereon a predetermined positive pressure and/or negative pressure.

Manufacturing method of metal paste

An oxide superconductor current lead in which generation of Joule heat at joint portions with a system side conductor and a power supply side conductor is reduced with use of an oxide superconductor with less heat penetration into a super conducting equipment system is provided. A columnar oxide superconductor molten bodies (interelectrode superconductor, in-electrode superconductorsand) are produced, the in-electrode superconductorand a left end portion of the interelectrode superconductorare placed into a power supply side metallic electrode, and the in-electrode superconductorand a right end portion of the interelectrode superconductorare similarly placed in a system side metallic electrode, then degassed joining metal is used to join them to form an oxide superconductor current lead, a power supply side conductorfrom a power supply is joined to the power supply side metallic electrode, and a system side conductorfrom a superconducting system side is joined to the system side metallic electrodewith use of respective clampsand

Oxide superconductor current lead and method of manufacturing the same, and superconducting system

A composite conductor suitable as a connecting conductor that includes a superconductor and is capable of reducing the generation of Joule heat in a joint part between the system side and power-supply sides of a superconductor apparatus. A composite conductorincludes a superconductorprovided continuously in the flowing direction of the electric current, and a metal conductorjoined with the superconductorand provided at least at a joint part with mating conductorsto be joined, wherein the electric current is fed and received between the metal conductorand the mating conductorsby joining the metal conductorand the mating conductorsand wherein the superconductoris arranged in the metal conductorso as to be approximately parallel to the joint surface (joint interface) between the metal conductorand the mating conductors

Composite conductor, superconductive apparatus system, and composite conductor manufacturing method

An oxide superconductor which exhibits an uniform and high critical current is disclosed. Further, a method of manufacturing this oxide superconductor is disclosed, namely, a RE&mdash;Ba&mdash;Cu&mdash;O oxide superconductor (RE is one or more kinds of rare earth elements including Y) by performing a treatment, which includes at least a burning process to be performed in a range of temperatures that are higher than a melting point of a raw material mixture containing a RE-compound raw material, Ba-compound raw material and a Cu-compound raw material, on the raw material mixture. This method further includes a step of crushing the raw material mixture into particles and establishing the mean particle diameter of one or all of the raw materials as ranging from 50 to 80 &mgr;m.

Oxide superconductor

An oxide superconductor which has high mechanical strength and exhibits favorable magnetic properties and high resistance to environment. Further, a method of manufacturing this oxide superconductor, namely, a method of manufacturing a RE--Ba--Cu--O oxide superconductor (RE is one or more kinds of rare earth elements including Y) by performing a treatment, which includes at least a burning process to be performed in a range of temperatures that are higher than the melting point of a raw material mixture containing a RE-compound raw material, a Ba-compound raw material and a Cu-compound raw material, on the aforesaid raw material mixture. This method further comprises the addition step of adding 1 to 30 in percent by weight (wt %) of Ag to the raw material mixture, and the crystallization step of melting the raw material mixture, to which Ag is added, at a temperature that is not lower than a temperature at which the raw material mixture is decomposed and fused into the RE.sub.2 BaCuO.sub.5 phase and a liquid layer, and then lowering the temperature of the aforesaid raw material mixture to a temperature close to a temperature, at which a REBa.sub.2 Cu.sub.3 O.sub.7-X phase crystallizes, and subsequently bringing a seed crystal, which meets the following condition: (the temperature at which the REBa.sub.2 Cu.sub.3 O.sub.7-X phase of the seed crystal)&gt;(the temperature at which the REBa.sub.2 Cu.sub.3 O.sub.7-X phase of the aforesaid raw material to which Ag is added), into contact with the aforesaid raw material mixture and then performing crystallization by using this seed crystal as a starting point.

Method of manufacturing oxide superconductor containing Ag and having

An oxide superconductor which has high mechanical strength and exhibits favorable magnetic properties and high resistance to environment. Further, a method of manufacturing this oxide superconductor, namely, a method of manufacturing a RE--Ba--Cu--O oxide superconductor (RE is one or more kinds of rare earth elements including Y) by performing a treatment, which includes at least a burning process to be performed in a range of temperatures that are higher than the melting point of a raw material mixture containing a RE-compound raw material, a Ba-compound raw material and a Cu-compound raw material, on the aforesaid raw material mixture. This method further comprises the addition step of adding 1 to 30 in percent by weight (wt %) of Ag to the raw material mixture, and the crystallization step of melting the raw material mixture, to which Ag is added, at a temperature that is not lower than a temperature at which the raw material mixture is decomposed and fused into the RE.sub.2 BaCuO.sub.5 phase and a liquid layer, and then lowering the temperature of the aforesaid raw material mixture to a temperature close to a temperature, at which a REBa.sub.2 Cu.sub.3 O.sub.7-x phase crystallizes, and subsequently bringing a seed crystal, which meets the following condition: (the temperature at which the REBa.sub.2 Cu.sub.3 O.sub.7-x phase of the seed crystal)&gt;(the temperature at which the REBa.sub.2 Cu.sub.3 O.sub.7-x phase of the aforesaid raw material to which Ag is added), into contact with the aforesaid raw material mixture and then performing crystallization by using this seed crystal as a starting point.

Oxide superconductor containing Ag and having substantially same crystal

An oxide superconductor which exhibits an uniform and high critical current density. Further, a method of manufacturing this oxide superconductor, namely, a RE--Ba--Cu--O oxide superconductor (RE is one or more kinds of rare earth elements including Y) by performing a treatment, which includes at least a burning process to be performed in a range of temperatures that are higher than a melting point of a raw material mixture containing a RE-compound raw material, Ba-compound raw material and a Cu-compound raw material, on the raw material mixture. This method further comprises a step of crushing the raw material mixture into particles and establishing the mean particle diameter of one or all of the raw materials as ranging from 50 to 80 .mu.m.

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Tokyo, Japan

Shuichi Kohayashi