Sumitomo Electric Industries, Limited

Other

Agency of Industrial Science and Technology

Japan Atomic Energy Research Institute

Japan Atomic Energy Institute

I. Sumitomo Electric Industries, Ltd.

Akira Yamakawa

Masaya Miyake

Takao Nishioka

Kenji Matsunuma

Takehisa Yamamoto

Seiji Nakahata

Hisao Takeuchi

Koichi Sogabe

Osamu Komura

Takahiro Matsuura

Hitoyuki Sakanoue

Akira Sasame

Takashi Matsuura

Matsuo Higuchi

Yasushi Tsuzuki

Chihiro Kawai

Kouichi Sogabe

Tomoyuki Awazu

Jin-Joo Matsui

Masashi Yoshimura

Masamichi Yamagiwa

Eiji Kamijo

Tetsuya Katayama

Norio Yasuoka

Kaoru Murabe

Yoshihiko Doi

Koji Yamaguchi

Yasushi Ito

Koichi Niihara

Michimasa Miyanaga

Tetsuya Abe

Osamu Yamada

Atsushi Kimura

Kohei Shimoda

Yoshio Murakami

Yasuhisa Yushio

Mitsue Koizumi

Jin-Joo Park

Nobuo Ogasa

Yoshinari Miyamoto

Masaaki Honda

Takeshi Satoh

Yoshinobu Takeda

Yoshishige Takano

Akira Yamaguchi

Hiromu Izumida

Seiji Hiroki

Shin-ichi Yamagata

Mitsuo Osada

Shinichi Yamagata

Harutoshi Ukegawa

Akira Doi

Koji Watari

Fumihiro Wakai

Tadashi Igarashi

Hitoshi Akazawa

Tomoyuki Awatsu

Kouiti Sogabe

Kozo Ishizaki

Douiti Sogabe

Hasaya Miyake

Naoki Kondoh

Yoshihiro Obata

Process for molding ceramics

A highly reliable metallized Si N ceramic having a metallizing layer of high bonding strength on the surface of a highly heat-conductive, mechanically-strong Si N ceramic. A metallizing layer including 0.01 to 20% silicon by weight in terms of silicon is formed on the surface of a silicon nitride ceramic including 0.01 to 10% free silicon by weight and having a thermal conductivity of 50 W/mK or more and a bending strength of 600 MPa or more. The silicon component in the metallizing layer is either introduced from the silicon nitride ceramic by diffusion or included in a metallizing paste beforehand.

Metallized silicon nitride ceramic and fabricating process thereof as well as metallizing composite for the process

A slurry Si-base composition comprising an Si powder having a thickness of a surface oxide film ranging from 1.5 to 15 nm, 50 to 90% by weight of water, 0.2 to 7.5% by weight, in terms of oxide, of a sintering aid and 0.05 to 3% by weight of a dispersant, the Si-base composition having a pH value adjusted to 8-12. This slurry Si-base composition is produced by a process which comprises subjecting Si powder to oxidation treatment at 200 to 800&deg; C. in air, adding 50 to 90% by weight of water, 0.2 to 7.5% by weight, in terms of oxide, of a sintering aid and 0.05 to 3% by weight of a dispersant to the oxidized Si powder and performing such a pH adjustment that the resultant mixture has a pH value of 8 to 12. The slurry Si-base composition not only enables producing a ceramic of Si N at a lowered cost without the need to install explosionproof facilities but also allows the obtained Si N ceramic having a relative density of at least 96% and a flexural strength of at least 800 MPa can be obtained.

Si3N4 ceramic, Si-base composition for production thereof and processes for producing these

A method of manufacturing a sliding component comprising a main body made of a non-carburized heat-hardened steel and a member adapted to form at least one sliding face of sliding faces of the sliding component and heat-joined to the main body, in which the steel-made main body is heat-hardened before heat-joining to the member and the heat-joining between the main body made of the heat-hardened steel and the member is conducted at a lower temperature than the temperature at which the heat-hardened main body has been heat-hardened. The sliding component is superior in hardness and abrasion resistance and is readily manufactured at a reduced cost.

Method of manufacturing a sliding component

A slurry Si-base composition comprising an Si powder having a thickness of a surface oxide film ranging from 1.5 to 15 nm, 50 to 90% by weight of water, 0.2 to 7.5% by weight, in terms of oxide, of a sintering aid and 0.05 to 3% by weight of a dispersant, the Si-base composition having a pH value adjusted to 8-12. This slurry Si-base composition is produced by a process which comprises subjecting Si powder to oxidation treatment at 200 to 800&deg; C. in air, adding 50 to 90% by weight of water, 0.2 to 7.5% by weight, in terms of oxide, of a sintering aid and 0.05 to 3% by weight of a dispersant to the oxidized Si powder and performing such a pH adjustment that the resultant mixture has a pH value of 8 to 12. The slurry Si-base composition not only enables producing a ceramic of Si,N,at a lowered cost without the need to install explosionproof facilities but also allows the obtained Si,N,ceramic having a relative density of at least 96% and a flexural strength of at least 800 MPa can be obtained.

Silicon nitride sinter having high thermal conductivity and process for

A silicon nitride sintered body prepared through a nitriding reaction of Si, consists of crystal grains mainly composed of silicon nitride and/or SIALON and a grain boundary phase. The grain boundary phase includes a first component including at least one element selected from a group of Na, K, Mg, Ca and Sr and a second component including at least one element selected from a group of Y and lanthanoid series elements. The molar ratio of the first component to the second component is in the range of 1:1 to 6:1 in terms of oxides. The mean breadth and the mean length of the crystal grains are not more than 0.1 .mu.m and not more than 3 .mu.m respectively, and the standard deviation of the mean length in the sintered body is within 1.5 .mu.m. Especially, the mean breadth of the crystal grains is at least 0.4 .mu.m and not more than 0.9 .mu.m.

Silicon nitride sintered body, method of preparing the same and nitrided

A silicon nitride ceramic sliding member which includes Si.sub.3 N.sub.4 grains as a main component and is shaped or controlled in dimensions through hot plastic working wherein the Si.sub.3 N.sub.4 particles mainly includes .beta.-type columnar crystal grains. The ceramic sliding member is produced by the step (I) of preparing a preform made of silicon nitride ceramic sintered body including Si.sub.3 N.sub.4 grains as a main component wherein the average grain size (average grain size in minor axis in the case of .beta.-type columnar crystal grains) of the Si.sub.3 N.sub.4 grains is at most 0.5 .mu.m, and the hot plastic working step (II) of placing the preform in a mold and effecting hot plastic deformation of the preform for shaping or dimensional control thereof while simultaneously increasing the average aspect ratio of the .beta.-type columnar crystal grains. The resultant sliding member has excellent sliding properties, a high mechanical strength and a high reliability at a low cost without resort to grinding or the like for shaping thereof.

Process for producing silicon nitride sliding member

Joint body of aluminum and silicon nitride and method of preparing the

A device for producing a ceramic sintered body consisting essentially of a mixing trough for mixing ceramic powder with water to form a slurry, the mixing trough having stirring blades, a separate slurry circulation conduit and a slurry mixing deflocculating unit, said separate slurry circulation conduit connecting said mixing trough and said deflocculating unit, said slurry mixing unit deflocculating said powder which has been flocculated with no grinding of powder by means of causing a high-speed shear flow and a high-speed contraction flow in the slurry, said slurry being repeatedly circulated form said slurry mixing unit to said mixing trough through said separate slurry circulation conduit.

Device for producing ceramic sintered body

A porous ceramic film which is formed onto and bonded to an oxide layer provided on the surface of a porous base, the film composed of finely deposited particles comprising at least one compound including (a) at least one selected from the group consisting of Si, B and Al or the group consisting of the metals of the Groups IVa, Va and VIa and (b) at least one selected from the group consisting of C and N in which the particles are intertwined with each other and bonded to each other through the component of the oxide layer to form a three-dimensionally intertwined structure. This porous ceramic film is produced by forming the oxide layer on the base surface and then heating it to a temperature of at least of the liquid-phase formation temperature of the oxide layer in a gaseous atmosphere containing the above elements (a) and (b). The porous ceramic film has a high porosity, a good pressure resistance and a regulated pore size and is appropriate for a filter, a catalyst support, bioreactor or a structural material.

Porous ceramic film and process for producing the same

A silicon nitride ceramic porous body having excellent acid and alkali resistance, mechanical strength, and durability can be employed as a filter or a catalytic carrier. The silicon nitride porous body contains a plurality of silicon nitride crystal grains with pores formed in grain boundary parts thereof, or includes a body part and a pore part wherein the body part is formed by a plurality of silicon nitride crystal grains and the pore part forms a three-dimensional network structure. The body part is formed by at least 90 vol. % of silicon nitride crystal grains, which are directly bonded to each other. In order to prepare the finished ceramic porous body, a porous body compact which is mainly composed of silicon nitride, is brought into contact with an acid and/or an alkali so that a component other than silicon nitride is partially or entirely dissolved and removed from the compact. The compact is prepared from a mixed powder of silicon nitride powder and at least one of a rare earth compound powder, a transition metal compound powder, and a bismuth compound, which is heat treated in the temperature range from 1600.degree. C. to 2100.degree. C.

Method of preparing silicon nitride porous body

A process for the production of a silicon nitride sintered body which comprises heat-treating a stock of silicon nitride sintered body within a temperature range of from the temperature at which the internal friction of the stock exhibits a peculiar peak maximum minus 150.degree. C. to that plus 150.degree. C. A representative used in the process is one which is produced by mixing powdered silicon nitride with powdery sintering aids so as to give a powder mixture comprising 5 to 15% by weight (in terms of oxide) of at least one element selected from the group consisting of rare earth elements and aluminum, 0.5 to 5% by weight (in terms of oxide) of at least one element selected from the group consisting of Mg, Ti and Ca and the balance of Si.sub.3 N.sub.4, molding the powder mixture, and sintering the resulting compact in a nitrogen-containing atmosphere at 1500.degree. to 1700.degree. C.

Process for the production of silicon nitride sintered body

Ceramic sliding component

Sliding component and production method thereof

Growing community of inventors

Itami, Japan

Akira Yamakawa