Mitsubishi Chemical Corporation

The Japan Steel Works, Ltd.

Furuya Metal Co., Ltd.

Tohoku University

Tokyo Denpa Co., Ltd.

Tsuguo Fukuda

Yoshihiko Yamamura

Yuji Sasagawa

Osamu Wakao

Shigeharu Akatsuka

Keiichiro Matsushita

Yutaka Mikawa

Yuji Kagamitani

Toru Ishiguro

Makiko Kiyomi

Shinya Sato

Shinichi Nishiya

An object of the present invention is to manufacture single crystals of high quality on an industrial production scale by preventing impurities from being mixed in single crystals when the single crystals are produced by the solvothermal method. A pressure vessel body, in which a supercritical state is maintained, is made of heat resistant alloy, a portion of the pressure vessel body is open, a corrosion-resistant mechanical liningis provided on an inner face of the pressure vessel and on an entire outer circumferential edge of the opening, and the opening is sealed by an airtight mating face formed out of a corrosion-resistant mechanical lining, which is formed on the outer circumferential edge of the opening, and by an airtight mating face of the corrosion-resistant mechanical lining coveron an inner face of the coverthrough a corrosion-resistant gasket member. Since the pressure vessel body and the inner face of the cover are covered with the corrosion-resistant mechanical lining, corrosion can be prevented. The corrosion-resistant mechanical lining ensures the sealing property on the airtight mating face between the pressure vessel body and the cover and further effectively prevents corrosion in the airtight sealing portion and it becomes possible to repeatedly open and close the airtight sealing portion.

Method of manufacturing a pressure vessel for growing single crystals

Pressure vessel for growing single crystals

To provide a production method for a nitride crystal, where a nitride crystal can be prevented from precipitating in a portion other than on a seed crystal and the production efficiency of a gallium nitride single crystal grown on the seed crystal can be enhanced. In a method for producing a nitride crystal by an ammonothermal method in a vessel containing a mineralizer-containing solution, out of the surfaces of said vessel and a member provided in said vessel, at least a part of the portion coming into contact with said solution is constituted by a metal or alloy containing one or more atoms selected from the group consisting of tantalum (Ta), tungsten (W) and titanium (Ti), and has a surface roughness (Ra) of less than 1.80 &#x3bc;m.

Production method, production vessel and member for nitride crystal

A material is presented that exhibits excellent corrosion resistance to supercritical ammonia and is suitable for a supercritical ammonia reactor. An Ni-based corrosion resistant alloy includes from 15% or more to 50% or less by mass of Cr and any one or both of Mo and W, wherein a [(content of Mo)+0.5&#xd7;(content of W)] is from 1.5% or more to 8.5% or less by mass, a value of 1.8&#xd7;[% content of Cr]/{[% content of Mo]+0.5&#xd7;[% content of W]} is from 3.0 or more to 70.0 or less and the balance is Ni and an unavoidable impurity. The alloy may be used to configure a supercritical ammonia reactor or the material is coated on a surface that contacts with a supercritical ammonia fluid. The alloy exhibits excellent corrosion resistance to supercritical ammonia and a mineralizer added the supercritical ammonia. The safety and reliability of an apparatus can be improved, the producing cost can be reduced, the apparatus lifetime can be extended and the running cost can be reduced.

Ni-based corrosion resistant alloy and corrosion resistant member for supercritical ammonia reactor made of the alloy

Growing community of inventors

Muroran, Japan

Yoshihiko Yamamura