Fuji Electric Co., Ltd.

National Research Institute for Metals

Chubu Electric Power Company, Inc.

Tatsuo Take

Michiru Fujita

Tadashi Morita

Toshiaki Watanabe

Akira Fukuzawa

Motoo Yamazaki

Kazuyuki Sakuraya

Makoto Yoshida

Hisaji Shinohara

Kengo Kainuma

Masaki Sakuma

Shunichi Hatakeyama

Masayuki Furusawa

Kazuro Shibata

Hiromi Iwai

Tsuneki Shinokura

Hideaki Tadano

Katsuro Shiozaki

To provide a Cu-Cr alloy electrode material, a mixture of Cu and cr materials at a predetermined ratio is heated until the mixture has been entirely melted, and the molten metal obtained is quenched to precipitate fine Cr particles in a Cu base. Since Cr is melted into Cu before quenching, and then Cr precipitates, Cr particles finer than those in the sintering or infiltration method can disperse in a Cu base. This invention prevents defects such as voids in the structure and the weakening of the fusion of Cu and Cr or failure of Cr to precipitate into the Cu base caused by oxide films on the surface of the Cr particles, thereby providing a fine alloy structure.

Method for manufacturing electrode material for vacuum circuit breaker

A cooling water conduit extending through a segment of a crucible is curved inward in the portion around a molten metal tapping hole.

Levitation melting furnace

In addition to a first driving device which moves only a lower crucible, and a first control device which controls the first driving device, a second driving device which changes the vertical relative position of an upper crucible and an induction coil, and a second control device which controls the second driving device are disposed, whereby the relative positions of the upper and lower crucibles and the induction coil can freely be changed. Consequently, the relative positions of the induction coil and the upper and lower crucibles can adequately be set in whole of the operation period from the initial operation stage to the final operation stage, in accordance with the position of a melting zone in the top portion of a material to be melted which grows as a result of continuously charging chips.

Levitating and melting apparatus and method of operating the same

Apparatus to float and melt particularly small pieces of high-melting point metal continuously while making the amount of meltable liquid metal greater than the capacity of a crucible. A conductive crucible having segments includes an upper cylindrical crucible portion and a lower closed-end crucible portion. An induction coil is arranged outside the upper crucible portion, whereas an induction coil is arranged below the induction coil. The lower crucible portion is in contact with the upper crucible portion and located on the inside of the induction coil at the initial melting stage. The lower crucible portion is lowered as a columnar metal grows and solidifies between molten metal and the lower crucible portion. A continuous feeder continuously feeds cold material. A molten metal surface thermometer and a molten metal surface level gauge are arranged above the crucible. The operation of the continuous feeder is regulated within a desired range of values of the molten metal surface thermometer. On the other hand, the lower crucible portion is successively lowered within a desired range of values of the molten metal surface level gauge.

Float melting apparatus and method employing axially movable crucibles

A plurality of segments 12 respectively formed of an electrically insulated conductive material such as copper or the like are disposed inside an induction coil 1 in the peripheral direction of the induction coil 1 to thereby construct a crucible 3. There is formed a small cylindrical hole 4 in the center of the bottom portion of the crucible 3. A magnetic flux is allowed to enter the crucible 3 from slits 15 respectively formed between the hole 4 and segments 12 and is then interlinked with an object to be heated. The slits 15 respectively defined by mutually adjoining segments 12 are arranged such that the width of the bottom portion thereof is greater than that of the cylindrical portion thereof. When the width of the slit in the bottom portion is increased, then a leakage flux to the crucible is increased which in turn increases a levitation force F. If there are further formed bottom slits only in the bottom portions of the segments to thereby increase the number of the slits in the bottom portion to be greater than that of the slits in the cylindrical portion, then the leakage flux is increased to thereby increase the levitation force F, and also the fused metal is supported at multiple points, which increases the stability S thereof.

Levitating and fusing device

Growing community of inventors

Kawasaki, Japan

Tatsuo Take