Composite powder particle, composite body and method of preparation
AssigneeSumitomo Electric Industries, Ltd.
InventorBenno Lux
Life of this patent
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Abstract
A composite powder particle, consisting of a core and a coating, and consisting either completely or partly of a superhard matter different from that of the core, and being prepared by means of a special method, at which the superhard matter is at least partly formed from a gaseous phase at sub-pressure and at temperatures below 1200.degree. C.
Claims14
A method of making composite powder particles comprising an inner core, which is enclosed by a coating having a thickness between 0.1 and 5000 .mu.m and comprising a superhard material having a Vickers hardness of more than 3500, which material is different from the core, the core and the coating comprising diamond or modification of diamond, the materials of the core and coating being different in chemical or physical properties with respect to each other characterized in, that the cores are coated in a chemical gas phase deposition procedure by the aid of gas flow in motion, at a temperature between 500.degree. and 1200.degree. C. and a pressure below 500 Torr, at which the gas consists either of
- a) hydrogen and CH.sub.4 or another gaseous or vaporous carbon compound with or without addition of noble gases or
- b) a gaseous or vaporous boron compound or a boron and nitrogen containing compound with or without hydrogen, nitrogen, halide or noble gas addition
- and at least one of the gases being supplied by a physical or chemical procedure in an excited state and the gas mixture being brought into contact with a powderous substrate in a CVD-reactor in which solid bodies are floating.
A method of preparing a powder of a superhard matter, characterized in, that composite powder particles comprising an inner core, which is enclosed by a coating having a thickness between 0.1 and 5000 .mu.m and comprising a superhard material having a Vickers hardness of more than 3500, which material is different from the core, possibly after preceding disintegration of the particles, are subjected to a chemical reaction, which dissolves the cores of the composite powder particles and the superhard matter remains.
A method of making composite powder particles comprising an inner core of hard material which is enclosed by a coating having a thickness between 0.1 and 5000 .mu.m and comprising a superhard material having a Vickers hardness of more than 3500, which material is different from the core, the hard material of the inner core being selected from the group consisting of a carbide, nitride, boride, phosphide, sulphide, silicide, oxide, oxynitride, oxycarbide, oxycarbonitride, a non-oxide silicon ceramic, SiAlON or mixture thereof, characterized in that the cores are coated in a chemical gas phase deposition procedure by the aid of gas flow in motion, at a temperature between 500.degree. and 1200.degree. C. and a pressure below 500 Torr, at which the gas consists either of
- a) hydrogen and CH.sub.4 or another gaseous or vaporous carbon compound with or without addition of noble gases or
- b) a gaseous or vaporous boron compound or a boron and nitrogen containing compound with or without hydrogen, nitrogen, halide or noble gas addition
- and at least one of the gases being supplied by a physical or chemical procedure in an excited state and the gas mixture being brought into contact with a powderous substrate in a CVD-reactor in which solid bodies are floating.
Dependencies are inferred from the claim text.