Hitachi, Ltd.

Yoshiyuki Yasutomi

Masahisa Sobue

Tadahiko Miyoshi

Nobuyuki Yamashita

Hiroshi Nagase

Yukio Saito

Kiyohiko Tanno

Kousuke Nakamura

Shigeru Kikuchi

Junji Sakai

Motoyuki Miyata

Shoji Arimoto

Fumio Jooraku

Mitsuo Nakagawa

Hideki Kita

Satoru Ogihara

Kunihiro Maeda

Yuichi Sawai

Hirokazu Inoue

Hideo Arakawa

Katsuo Wada

Yasuo Matsushita

Akio Chiba

Hironori Kodama

Hideki Tamaki

Takahiko Okouchi

Tomohito Oyagi

Seiji Watahiki

Fiber bundle reinforced composite material useful for various high temperature structural members having excellent strength, toughness and resistance to oxidation and a process for producing the same. The fiber bundle reinforced composite material is reinforced with fiber bundles each having a plurality of continuous inorganic fibers bundled with medium such as carbon, being oriented in one, two or three directions, or randomly in the matrix which is reinforced with nano-sized particles precipitated. The fiber bundle reinforced composite material has a desired orientation of fibers and enables production of fiber bundle reinforced composite members having excellent strength and toughness.

Process for producing fiber reinforced composite

An apparatus comprising a plurality of sliding members, at least one of the sliding members being a self-lubricating-function sliding member characterized by containing a precursor compound which produces a solid-lubricating compound during sliding by reacting with an atmosphere in which the sliding member is used or a component of a material with which the sliding member is in sliding contact.

Apparatus having sliding member with precursor material providing solid

The surface of a member formed of at least one kind of ceramics, metals and C/C composites, is covered with an outermost surface oxide covering layer having a stability against the environment in the atmospheric air at 1500.degree. C.; and a self-recoverable layer as an intermediate layer formed between the outermost surface oxide covering layer and the surface of the member. The self-recoverable layer has an oxidizing rate greater than that of the outermost surface covering layer for recovering cracks generated on the outermost surface covering layer, and a compound produced by the self-recoverable layer has the same phase as in the outermost surface covering layer. To achieve the optimum self-recovering function at high temperatures, the outermost surface oxide covering layer may be made of a stable oxide having a vapor pressure of 1.times.10.sup.-4 /m.sup.2 or less in the atmospheric air at 1500.degree. C., and the oxidized product material from the self-recoverable layer contains an oxide having the same composition as that of the outermost surface oxide covering layer.

Self-recoverable covering material and method for fabricating the same

A method of estimating non-destructively the life expectancy of ceramic members, at least a surface layer of which is made of ceramics, is disclosed. The method comprises measuring a variation in at least one of physical characteristics of said ceramic members including color, grain size, electroconductivity and Young's modulus and estimating the life expectancy of the ceramic members on the basis of the predetermined relationship between the life of said ceramics and the physical characteristics. The method is excellent in estimation of the life expectancy of ceramic members of gas turbines or nuclear fusion reactor since the life expectancy of the members to be inspected can easily be estimated in a short time without fracturing the members.

Method of non-destructively estimating life of ceramic member

To provide diagnosis of service life and maintenance requirements, a sintered ceramic body which in use is subjected to stress and undergoes change with time as a result of the stress is provided with an electrically conductive element in contact with the sintered ceramic material The element has a measurable electrical resistance which increases in dependence on the change of the ceramic body. This permits information to be obtained about said change of said body. Measuring means for the electrical resistance is connected to the conductive element. The electrically conductive element as seen in cross-section, may comprise a bundle of elongate members such as fibers or whiskers.

Ceramic body and method and apparatus for detecting change thereof

The invention provides a conductor comprising a reaction-sintered body of a conductive nitride produced from a powder of at least one metal selected from Ti, Zr, V, Nb, Ta, Cr, Ce, Co, Mn, Hf, W, Mo, Fe, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Yb, Lu, Th and Ni, and a process for producing such conductor by heating a molding containing a metal powder in a nitriding gaseous atmosphere containing no CO gas.

Conductive material and process for preparing the same

Disclosed is a ceramic composite which comprises particles of at least one inorganic compound selected from the group consisting of a carbide, a nitride, an oxide, a boride, a silicide and an oxy-nitride and particles and whiskers of Si.sub.3 N.sub.4, Si.sub.2 N.sub.2 O or SiO.sub.2. This ceramic composite is small in volume change on sintering, and provides heat resistance. In addition, the composite can absorb thermal shock by its voids. It can be used in association with ceramic heaters, current collectors, commutators for starter motors and alternators, and in other areas.

Process for producing ceramic compositions

Ceramic composite and process for production thereof

A casting method for manufacturing various types of ceramics products having an intricate configuration and a partly diversified wall thickness, such as compressor scroll blade and a screw rotor, by casting a slurry including ceramics, etc. in a mold, includes an arrangement wherein the mold is partly or entirely formed of a flexible gel material which can be melted by heating at a temperature lower than the boiling point of the dispersion medium, whereby the stresses generated when molding the product can be mitigated. Thus, the molding of a product having a high level of dimensional accuracy can be carried out with ease.

Slip casting method

The present invention is a composite ceramic structure having a porosity of 5 to 40% by volume comprising particles selected from the group consisting of grains and whiskers of at least one inorganic compound AB, where B is oxygen, nitrogen or carbon and A is any metal so the difference in electronegativity between A and B is less than 1.7; or particles selected from the group consisting of grains and whiskers of an inorganic compound, where there is a difference of 1.7 and higher between the components, and having layers of the inorganic compound AB formed on the surfaces of the particles. The particles are bonded together by silicon nitride particles having an average particle size of less than 0.2 micron. The composite ceramic structure is produced by sintering a shape composed of particles of AB or composed of particles having layers of AB formed on the surfaces of the particles in a gaseous atmosphere containing silicon and nitrogen to grow silicon nitride particles on the surfaces of the shaped inorganic particles.

High strength composite ceramic structure and process for producing the

An installation structure of integrated circuit devices, in which two or more types of integrated circuit devices of different base materials are installed onto the same installation substrate. Since the installation structure has a construction according to different characteristics such as a thermal conductivity, heat generation amount, thermal expansion coefficient and the like of the integrated circuit devices made of different materials, the reliability of each device and its connection and the reduction of the costs required for the cooling method can be presented.

Installation structure of integrated circuit devices

Composite ceramic materials and a method of the same are disclosed, in which a ceramic material mainly containing silicon nitride, and at least one compound selected from a group consisting of nitrides, carbides, borides, silicides, oxides and oxynitrides of elements belonging to IIIa, IIIb, IVa, IBb, Va, VIa and VIII are combined to form a sintered body, and particles and whiskers of the ceramic material and compound are interlocked with each other and fixed so that the sintered body has a porosity of 5 to 30%. In the above composite ceramics, the particle of the compound are coupled with each other through the whisker or particle of the ceramic material. Accordingly, the composite ceramics are small in charge rate of size due to sintering, and are excellent in tenacity, heat resisting property and thermal shock resisting property. Further, the resistivity of the sintered body can be varied by changing the mixture ratio of ceramic material and compound.

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Katsuta, Japan

Yoshiyuki Yasutomi