National Institute for Materials Science

Central Japan Railway Company

Hitachi, Ltd.

National Research Institute for Metals

Japan As Represented by Director General of National Research Institute for Metals

Hitoshi Kitaguchi

Hiroaki Kumakura

Kazumasa Togano

Hideyuki Yamada

Michiya Okada

Hiroki Fujii

Kazuhide Tanaka

Masaya Takahashi

Yasuo Iijima

Akihiro Kikuchi

Takayuki Nakane

Hanping Miao

Akiyoshi Matsumoto

Kazuto Hirata

Masazumi Hirakawa

Nobuhito Uchiyama

Hirohaki Kumakura

The present disclosure provides a copper-coated aluminum wire material including an aluminum wire material and a copper thin film coating the aluminum wire material that a space factor of the thin copper film is in the range of 0.2% to 4%.

Copper-coated aluminum wire material and production method therefor

In a fabrication method of a MgBsuperconducting tape and wire by filling a tube with a MgBsuperconducting powder and forming it into a tape or wire, a fabrication method of a MgBsuperconducting tape (and wire) which is characterized by using a MgBsuperconducting powder having a high critical current density (J) owing to its lowered crystallinity and having potential for excellent grain connectivity as the MgBsuperconducting powder. Provided are a fabrication method of a MgBsuperconducting tape and wire which can fabricate a MgBsuperconducting tape and wire having a level of Jsufficiently high for practical applications and homogeneous quality throughout its length by an ex-situ process employing a material of the composition suitable for its working environment as the sheath material, and a MgBsuperconducting tape and wire thereby fabricated.

[object Object]

The present invention provides a method for producing a MgBsuperconductor, comprising compacting and heating a mixture comprising Mg or MgHpowder and B powder, wherein said mixture comprises SiC powder and an aromatic hydrocarbon, and a MgBsuperconductor having a higher critical current density (J) than that of the known MgBsuperconductors added SiC only or added an aromatic hydrocarbon only such as benzene.

By adding an aromatic hydrocarbon such as benzene to the powder mixture of magnesium (Mg) or magnesium hydride (MgH) and boron (B) as raw materials of a superconductor MgB, high superconducting critical current density (Jc) is obtained.

MgB2 superconductor, its wire, and a manufacturing method thereof

In a metal sheath MgBsuperconducting wire, it is intended to achieve a wire having increased current density and a long length at the same time, by densitying superconducting core part. The superconducting wire is manufactured by forming diffusion hardened layer on the inner surface of the sheath such that the hardness of the inner surface becomes higher than that of the outer surface, filling MgBsuperconductor, and further if necessary, a critical current density increasing material such as indium, copper, and tin, in a metal sheath, to subject it to wire drawing. For the metal sheath, a material with toughness such as steel is used. Even if the sheath is made to a long wire, it does not break, thereby, enabling to density superconducting core part.

Metal sheath magnesium diboride superconducting wire and its manufacturing method

A method of producing a composite material of a bismuth 2212 phase and a metallic substrate, wherein the first and second baking are conducted as an isothermal heat treatment. According to this process, temperature control is easy, high productivity is obtained, and the critical current density is improved.

Method of producing oxide superconductive composite material

In a process in which a composite consisting of a metallic base and a superconductor mainly containing a Bi,Sr,CaCu,O,superconducting phase is formed into a composite wire or wire, the composite is subjected to calcination and cold working before heat treatment for crystallization from a partial molten state.

Making of bismuth 2212 superconducting wire or tape

Growing community of inventors

Tsukuba, Japan

Hitoshi Kitaguchi