Ube Industries, Inc.

Masahiro Tokuse

Takemi Yamamura

Yoshiharu Waku

Michiyuki Suzuki

Tadashi Iwai

Takashi Kawahito

Teruhisa Furushima

Tadashi Yamamoto

Kenji Matsunaga

Disclosed are water soluble core wherein a particulate refractory material is combined with a binding agent comprising Na.sub.2 CO.sub.3, Na.sub.2 O . NSiO.sub.2 where n is 0.5 to 4, and SiO.sub.2 as ingredients and a process for producing the water soluble core. The process comprises mixing the particulate refractory material with a water glass, casting the mixture of the particulate refractory material and the water glass, hardening the casting by CO.sub.2 gas, and calcining the casting at between 100.degree. C. and a temperature less than that of an endothermic peak of the water glass in differential thermal analysis. Also, a process for die casting a metal is disclosed using the water soluble core which process comprises pre-heating the water soluble core from a temperature of 300.degree. C. below a melting point of the metal to a temperature of the endothermic peak.

Water soluble cores, process for producing them and process for die

A fiber-reinforced metal composite (aluminum-matrix composite) consisting essentially of reinforcing fibers and an aluminum alloy containing 6 to 11 wt. % of nickel of a metal matrix.

Fiber-reinforced metal composite

A fiber-reinforced metal composite consisting essentially of continuous reinforcing fibers disposed in an aluminum alloy matrix containing about 0.005 wt % of cobalt.

Continuous fiber-reinforced Al-Co alloy matrix composite

A hybrid fiber-reinforced plastic composite material comprising a matrix of a plastic and hybrid fibers consisting of inorganic fibers and at least one kind of fibers selected from the group consisting of carbon fibers, glass fibers, boron fibers, aramide fibers and silicon carbide fibers having a carbon core, wherein

Hybrid fiber-reinforced plastic composite material

An inorganic fiber-reinforced metallic composite material comprising a matrix of a metal or its alloy and inorganic fibers as a reinforcing material, characterized in that

Inorganic fiber-reinforced metallic composite material

An inorganic fiber-reinforced ceramic composite material comprising a matrix of a ceramic and inorganic fibers as a reinforcing material, characterized in that (a) the inorganic fibers are specified inorganic fibers containing silicon, either titanium or zirconium, carbon and oxygen, (b) the ceramic is at least one material selected from the group consisting of carbides, nitrides, oxides, glass ceramics, graphite and specified inorganic materials containing silicon, either titanium or zirconium, carbon and oxygen, (c) the inorganic fibers have an initial reaction degradation speed of not more than 0.35 kg/mm.sup.2.sec.sup.-1 and a tenacity reduction ratio of not more than 40% during the production of the composite material, (d) the composite material has a critical stress intensity factor about 2 to 7 times as high as that of said matrix alone, and (e) the composite material has a bending strength reduction ratio, measured by a thermal shock fracture resistance measuring method, of not more than about 10% after it is heat-treated in air at 800.degree. to 1300.degree. C., immediately then dipped in water at room temperature, and then dried.

Inorganic fiber-reinforced ceramic composite material

An inorganic fiber-reinforced ceramic composite material comprising a matrix of a ceramic and inorganic fibers as a reinforcing material, characterized in that (a) the inorganic fibers are specified inorganic fibers containing silicon, either titanium or zirconium, nitrogen and oxygen, and (b) the ceramic is at least one material selected from the group consisting of carbides, nitrides, oxides, glass ceramics, graphite and specified inorganic materials containing silicon, either titanium or zirconium, nitrogen and oxygen.

A method of preparing polycarbosilanes having high molecular weight and also having the major structural unit of silicon-carbon linkage. The method comprises heating a polysilane at 50.degree.-600.degree. C. in atmosphere of an inert gas and distilling out a low molecular weight polycarbosilane fraction having the number mean molecular weight of 300-600, followed by polymerizing the fraction by heating it at 250.degree.-500.degree. C. in atmosphere of an inert gas. The polycarbosilane obtained by the method of the present invention is useful for the precursor of preparing silicon carbide fibres and shaped articles.

Method of preparing polycarbosilanes

The carbonitrides of metals of Groups IV, V and VI of the Periodic Table are prepared by calcining a precursor obtained by (i) reacting the reaction product of ammonia and the halide of a metal selected from the group consisting of Groups IV, V and VI of the Periodic Table of Elements with polyphenol, or (ii) reacting the reaction product of polyphenol and the halide of a metal selected from the group consisting of Groups IV, V and VI of the Periodic Table of Elements with ammonia, the amount of the polyphenol being within the range defined by the following relationship: ##EQU1## wherein a is the number of hydroxyl groups contained in one molecule of the polyphenol, b is the number of moles of the polyphenol and c is the number of moles of the metallic halide. The desired metallic carbonitride in the form of finely divided powder having a uniform size and excellent sintering properties can be obtained at low energy consumption.

Process for producing carbonitride of metal

The carbonitrides of metals such as those of Groups IV, V and VI of the Periodic Table are prepared by calcining a precursor obtained by (i) reacting the reaction product of ammonia and the halide of a metal with carbohydrate and/or polyvinyl alcohol, or (ii) reacting the reaction product of carbohydrate and/or polyvinyl alcohol and the halide of a metal with ammonia. The desired metallic carbonitride in the form of finely divided powder having a uniform size and excellent sintering properties can be obtained at low energy consumption.

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Ube, Japan

Masahiro Tokuse