The Japan Steel Works, Ltd.

National University Corporation Kitami Institute of Technology

Mitsubishi Materials Corporation

Ulvac, Inc.

Kiyoshi Aoki

Kazuhiro Ishikawa

Toshiki Kabutomori

Tsuyoshi Sasaki

Koichi Kita

Tomohiro Ueno

Takeshi Matsuda

Koichi c/o Mitsubishi Materials Corporation Kita

A hydrogen permeation/separation thin membrane including a Ni&#x2014;Ti&#x2014;Nb alloy. The Ni&#x2014;Ti&#x2014;Nb alloy is a cast foil material obtained by roll quenching and a refining heat treatment. The membrane has a thickness of 0.07 mm or less. The Ni&#x2014;Ti&#x2014;Nb alloy has the following: (a) a composition consisting of 10 to 47 atomic % of Nb, 20 to 52 atomic % of Ti, and a remainder containing 20 to 48 atomic % of Ni and inevitable impurities; and (b) an alloy structure where fine particles of a Nb-based solid solution alloy, in which Nb forms a solid solution with Ni and Ti in Nb, are dispersed in a basic structure made of a Ni&#x2014;Ti(Nb) intermetallic compound formed of a solid solution of a Ni&#x2014;Ti intermetallic compound, in which part of Ti thereof is replaced by Nb.

Hydrogen permeation/separation thin membrane

A hydrogen permeable module includes a hydrogen permeable membrane that permeates hydrogen, an outer peripheral part of the hydrogen permeable membrane being restricted, an inside of the outer peripheral part of the hydrogen permeable membrane being not restricted. The hydrogen permeable module permeates the hydrogen by constantly keeping a pressure of a primary side to a pressure that is equal to or more than a pressure of a secondary side. The inside of the outer peripheral part of the hydrogen permeable membrane is not restricted so as to be capable of expanding to the secondary side.

Hydrogen permeable module and usage thereof

An Nb&#x2014;Ti&#x2014;Co alloy having both good hydrogen permeability and good hydrogen embrittlement resistance comprises one of Fe, Cu or Mn as a fourth element, incorporating from 1 to 14 mol %. The content of Mn, if any, is preferably from 1 to 9 mol %. The desired hydrogen permeability can be attained by the (Nb, Ti) phase and the desired hydrogen embrittlement resistance can be attained by the CoTi phase, making is possible to obtain excellent hydrogen permeability and excellent hydrogen embrittlement resistance. None of Fe, Cu or Mn can impair these properties. Fe, Cu or Mn can replace some of the Co elements. Fe, Cu or Mn enhances the workability of the alloy.

Hydrogen permeable alloy

A (Nb, Ti) phase in an Nb&#x2014;Ti&#x2014;Co alloy is composed of a granular structure. The Nb&#x2014;Ti&#x2014;Co alloy is preferably subjected to heat treatment at 800&#xb0; C. or more so that the eutectic structure in the casted state can be changed to a granular structure. The Nb&#x2014;Ti&#x2014;Co alloy used there is preferably NbTiCo, (x&#x2266;70, 20&#x2266;y&#x2266;50 (mol %)). By properly predetermining the heating temperature and time, the resulting alloy exhibits improved hydrogen permeability in combination with a good hydrogen embrittlement resistance characteristic in the CoTi phase, making it possible to provide a practical hydrogen permeable membrane having an advantageously high performance.

Hydrogen permeable alloy and method for producing the same

An Ni&#x2014;Ti&#x2014;Nb based multiple phase alloy consists of a combined phase which comprises a phase for the hydrogen permeability and a phase for the resistance to hydrogen embrittlement. The alloy has a composition satisfying the formula: NiTiNbin which x=25&#x2dc;45 mol % and y=25&#x2dc;55 mol %. A metal membrane for hydrogen separation-purification is prepared using the alloy material. The alloy material is prepared by blending Ni, Ti and Nb and melting the blend. The metal membrane permits the hydrogen separation-purification and thus the resulting purified hydrogen gas can be used as a fuel and can be applied to fields of production of semiconductors.

Multiple phase alloys and metal membranes for hydrogen separation-purification and method for preparing the alloys and the metal membranes

In a multiphase hydrogen permeation alloy comprising a phase in charge of hydrogen permeation and a phase in charge of hydrogen embrittlement resistance, a structure in which the phase in charge of hydrogen permeability is continuously interconnected and in which more preferably the growth direction of the aforementioned phase in charge of hydrogen permeation lies aligned in the thickness direction of the permeation membrane. As the hydrogen permeation alloy, an Nb&#x2014;Ti&#x2014;Co alloy is exemplified, wherein the phase in charge of hydrogen permeability is made of an (Nb, Ti) phase and the aforementioned phase in charge of hydrogen embrittlement resistance is made of a CoTi phase. By virtue of the fact that the growth direction of the phase in charge of hydrogen permeation lies aligned in the thickness direction of the permeation membrane, the hydrogen permeation pass length becomes short to give further improved hydrogen permeation property.

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Hokkaido, Japan

Kazuhiro Ishikawa