Agency of Industrial Science and Technology

National Institute of Advanced Industrial Science and Technology

Japan As Represented by Director General of Agency of Industrial Science

Tani, Eiji

Eiji Tani

Kazuhisa Shobu

Tadahiko Watanabe

Kazushi Kishi

Morito Akiyama

Kazuo Kobayashi

Kunio Kimura

Eishi Maeda

Seiki Umebayashi

A visible-light-responsive three-dimensional fine cell-structured photocatalytic filter in accordance with the present invention includes a sponge-like porous structure (B) containing an anatase-type titanium oxide coating formed on a surface of a sponge-like porous structural body (A) which has a porosity of 85 vol % or more. The sponge-like porous structural body (A) is composed of one material selected from the group consisting of one metal selected from the group consisting of (a) to (e): (a) carbon and either or both of silicon and a silicon alloy; (b) silicon carbide and at least one material selected from the group consisting of silicon, a silicon alloy, and carbon; (c) silicon nitride and at least one material selected from the group consisting of silicon, a silicon alloy, carbon, and silicon carbide; (d) carbon; and (e) carbon and one metal selected from the group consisting of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, ruthenium, rhodium, palladium, silver, platinum, and gold.

Visible-light-responsive three-dimensional fine cell-structured photocatalytic filter, its manufacturing method and purifier device

A super-lightweight ceramic foam with a cellular structure effectively reinforced by ceramic short fibers, which has a density of 0.2 g/cmor less and a sufficient strength. The ceramic foam is prepared by evenly dispersing ceramic short fibers throughout a nonaqueous solvent through the use of the reactivity of metal alkoxide with the surface of the ceramic short fibers, adding into the nonaqueous solvent an aqueous slurry containing ceramic powder dispersed therein, allowing the evenly dispersed ceramic fibers to move into an aqueous phase separately from a nonaqueous solvent phase so as to obtain an aqueous slurry containing the ceramic fibers evenly dispersed therein, and foaming and firing the aqueous slurry.

Method of manufacturing a super-lightweight ceramic foam

A process produces a fiber-reinforced silicon carbide composite. The resulting composite has a high toughness where bundles of a reinforcing fiber are densely covered with glassy carbon derived from a resin to avoid deterioration of the strength, and it can easily be produced even in complicated shapes. Specifically, a fiber-reinforced silicon carbide composite is produced by preparing a fiber prepreg containing a powdered silicon and a resin and molding the prepreg to yield a green body having a desired shape, or laminating a fiber prepreg containing a resin and a woven fabric prepreg containing a powdered silicon and a resin in alternate order, and molding the laminate to yield a green body having a desired shape; carbonizing the green body at 900&deg; C. to 1350&deg; C. in an inert atmosphere; impregnating the carbonized body with a resin; firing the impregnated body again at 900&deg; C. to 1350&deg; C. in an inert atmosphere; performing the resin impregnation-carbonization procedure one to five times; subjecting the carbonized composite to reaction sintering at a temperature of 1300&deg; C. or more in vacuo or in an inert atmosphere to form open pores, and finally infiltrating molten silicon into the sintered body having open pores at a temperature of about 1300&deg; C. to 1800&deg; C. in vacuo or in an inert atmosphere.

Process for producing fiber-reinforced-silicon carbide composites

A fiber-reinforced silicon carbide composite is produced by preparing a fiber prepreg containing a powdered silicon and a resin and molding the prepreg to yield a green body having a desired shape, or laminating a fiber prepreg containing a resin and a woven fabric prepreg containing a powdered silicon and a resin in alternate order and molding the laminate to yield a green body having a desired shape; carbonizing the green body at 900&deg; to 1350&deg; C. in an inert atmosphere; subjecting the carbonized body to reaction sintering at a temperature of 1300&deg; C. or more in vacuo or in an inert atmosphere to form open pores; and infiltrating molten silicon into the sintered body having open pores at a temperature of about 1300&deg; to 1800&deg; C. in vacuo or an inert atmosphere.

Process for producing fiber-reinforced silicon carbide composites

The present invention provides a dense SiC-infiltrated composite material or a dense carbon-fiber-reinforced SiC-infiltrated composite material and a dense SiC-infiltrated composite material with granular carbon dispersed therein that are unlikely to bond to a carbon crucible and that have excellent heat and oxidation resistance. This composite material can be obtained by infiltrating molten carbon-silicide of Mo that is approximately expressed as Mo.sub.3 Si.sub.2 C or a eutectic mixture of carbon-silicide and silicon carbide into a silicon-carbide-based preform having 10 to 60 vol. % of continuous voids and then cooling and solidifying the melt.

High-temperature ceramics-based composite material and its manufacturing

Disclosed is a method for the preparation of a fiber-reinforced silicon carbide-based composite ceramic body having outstandingly high mechanical strengths even without using any sintering aids or without undertaking the hot-press sintering method. The method comprises impregnating carbon fibers or silicon carbide fibers with a slurry containing an elementary silicon powder, an organic resin, e.g., phenolic resins, and an organosilicon polymer, e.g., polysilastyrenes, according to a specified formulation and shaping the impregnated fibers into a green body which is subjected to a calcination treatment at 1300.degree.-1500.degree. C. in an inert atmosphere under normal pressure.

Method for the preparation of silicon carbide-based composite ceramic

The present invention provides a SiC-MoSi.sub.2 infiltration material with high heat-resistant property, which can be used at 1500.degree. C. under atmospheric condition, can be produced at lower manufacturing temperature, and can maintain high resistance to oxidation. This ceramic composite material with high heat-resistant property can be obtained by infiltrating aluminum silicide of molybdenum, which is expressed by a formula of Mo(Al.sub.x Si.sub.1-x).sub.2 (where 0.1&lt;x&lt;0.5) into a porous preform of silicon carbide having porosity of 10 to 50% in volume ratio.

Ceramic composite material with high heat-resistant property

A novel method is disclosed for the preparation of a silicon carbide-based composite ceramic body reinforced with carbon fibers having an outstandingly high mechanical strength. The method comprises impregnating carbon fibers with a mixture of fine silicon particles and a thermosetting resin such as a phenolic resin to give a carbon fiber compact body impregnated with the mixture, which is then subjected to a heat treatment at about 1400.degree. C. in an inert atmosphere so that the thermosetting resin is thermally decomposed to produce free carbon capable of reacting with the silicon particles without affecting the carbon fibers embedded in the matrix due to the preferential reactivity of the silicon particles with the free carbon produced from the resin thus not to decrease the recinforcing effect of the carbon fibers.

Method for the preparation of silicon carbide-carbon fiber composite

A process for producing a .beta.-sialon.silicon carbide complex includes mixing silicon nitride and silicon carbide with an aluminum alkoxide solution or a soluble aluminum salt solution and using the resulting homogeneous mixture as a starting material in forming a sintered body. The aluminum alkoxide solution or aluminum salt solution penetrates into the surface of each particle of the silicon nitride and silicon carbide, whereby the whole surface of each nitride and carbide particle is covered with aluminum alkoxide solution or aluminum salt solution, and homogeneous mixing is achieved. Therefore, defects such as pores, clusters of large grains, or unsintered parts are eliminated and the strength of the final sintered bodies is improved.

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Eiji Tani