Idemitsu Petrochemical Co., Ltd.

Ngk Spark Plug Company, Limited

Ngk Spark Plug Cp. Ltd.

Toshimichi Ito

Masakazu Watanabe

Satoshi Iio

Masaya Tsubokawa

Ikuo Hosoya

Nariyuki Hayashi

Masaaki Nosaka

Yasushi Seta

Ryoichi Tsunori

Satoshi Katsumata

Foaming propylene copolymer, and foamed particles and foams thereof

A diamond-coated body is prepared by coating a diamond film on the surface of a sintered body by means of vapor phase synthesis, the sintered body being so prepared by subjecting a sintered body prepared from ceramics based on silicon nitride to heat treatment at the temperature of 1,400.degree. C. to 1,700.degree. C. as to give a crystalline intergranular phase. The resulting diamond-coated body has excellent adhesion between the diamond film and the substrate and it is appropriately employed for cutting tools and so on because, when applied to the cutting tools, they can be used for cutting for a long period of time.

Diamond-coated bodies and process for preparation thereof

Diamond-coated body

The present invention concerns a method of producing a diamond thin film. A plasma-activated gas, obtained by exciting a starting material containing a carbon source gas, is brought into contact with a surface of a substrate, on which a diamond thin film is to be formed under the presence of an auxiliary member placed adjacent to a protruded portion present at the surface of the substrate. The diamond thin film is thereby formed on the substrate. An apparatus for producing a diamond thin film by means of a microwave plasma method has an auxiliary member placed adjacent to a protruded portion present at the surface of the substrate on which the diamond thin film is to be formed.

Method and apparatus for producing diamond thin films

Diamond-coated member and process for the preparation thereof

The present invention is directed to a method of producing a sintered hard metal having a diamond film wherein a gas that is obtained by activating a raw material gas containing 2 to 60 mol % of carbon monoxide and hydrogen gas is brought in contact with a sintered hard metal to form a diamond film, thereby a diamond film can be formed on said sintered hard metal with the adhesion of the diamond excellent.

Method of producing sintered hard metal with diamond film

The present invention provides a diamond coated sintered body characterized by having a diamond film formed by a gas phase synthesis method on the surface of a sintered body obtained from a mixture of tungsten carbide and at least one compound selected from the group consisting of carbide and nitride of silicon or boron and, if necessary, additionally at least one compound selected from the group consisting of carbide, oxide, nitride, carbonitride, carbonate, boride and organic compound of at least one element selected from the group consisting of metals and rare earth elements belonging to Groups Ia, IIa, IIIa, IVa, Va, IIIb and IVb of the Mendelejeff's periodic table.

Diamond coated sintered body

Method for synthesis of diamond

The following are disclosed: A method for synthesis of diamond which is characterized by contacting a gas obtained by excitation of carbon monoxide and hydrogen in such a ratio as carbon monoxide being at least 1 mol % per total of carbon monoxide and hydrogen with a substrate in the presence of a reducing metal. A method for synthesis of diamond which is characterized by contacting with a substrate a gas obtained by excitation of carbon dioxide and hydrogen mixed at such a ratio of carbon dioxide being 0.1-20 mol % per hydrogen. A method for synthesis of diamond by depositiong diamond on the surface of a substrate by introducing onto the surface of the substrate a plasma obtained from hydrogen and carbon source gas by irradiation of microwave in a plasma generator which is characterized in that progress of microwave oscillated from one microwave oscillator is divided and thus divided respective microwaves and led to a plurality of plasma generators. A diamond synthesis apparatus which is characterized by comprising a microwave oscillator for oscillation of microwave, a branched waveguide for dividing the microwave oscillated from said microwave oscillator and a plurality of plasma generators which are connected with said branched waveguide and have a substrate for deposition of diamond, respectively.

Method for synthesis or diamond

This invention provides a method for synthesis of diamond by contacting a substrate with a mixed gas of carbon source gas and hydrogen gas activated by irradiation with microwave to produce plasma, thereby to deposit diamond on the surface of the substrate wherein microwave is introduced from a plurality of directions to the substrate and an apparatus for synthesis of diamond which comprises at least one microwave oscillator which oscillates microwave, a plurality of waveguides for introducing from a plurality of directions the microwave oscillated from said microwave oscillator to a substrate for deposition of diamond, and a reaction chamber which is connected to said waveguides and in which diamond is deposited by generation of plasma thereby to form a diamond thin film on the surface of said substrate.

Growing community of inventors

Tokyo, Japan

Toshimichi Ito