Polycrystalline diamond and manufacturing method thereof
AssigneeSumitomo Electric Industries, Ltd.
InventorsKazuhiro Ikeda, Keiko Arimoto, Katsuko Yamamoto, Hitoshi Sumiya
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Abstract
Nano polycrystalline diamond is composed of carbon and a plurality of impurities other than carbon. A concentration of each of the plurality of impurities is not higher than 0.01 mass %, and the nano polycrystalline diamond has a crystal grain size (a maximum length) not greater than 500 nm. The nano polycrystalline diamond can be fabricated by preparing graphite in which a concentration of an impurity is not higher than 0.01 mass % and converting graphite to diamond by applying an ultra-high pressure and a high temperature to graphite.
Claims9
Polycrystalline diamond, comprising:
- carbon;
- and
- a plurality of impurities,
- the polycrystalline diamond having a concentration of each of said plurality of impurities not higher than 0.01 mass % and a crystal grain size not greater than 500 nm,
- the polycrystalline diamond having Knoop hardness not lower than 150 GPa, and
- the polycrystalline diamond fabricated by sintering graphite obtained by thermal decomposition of hydrocarbon having purity not lower than 99.99%, at a temperature not lower than 1500° C.
Polycrystalline diamond, comprising:
- carbon in which purity of a carbon isotope 12C is not lower than 99.9 mass %;
- and
- a plurality of impurities,
- the polycrystalline diamond having a concentration of each of said plurality of impurities not higher than 0.01 mass % and a crystal grain size not greater than 500 nm,
- the polycrystalline diamond having Knoop hardness not lower than 150 GPa, and
- the polycrystalline diamond fabricated by sintering graphite obtained by thermal decomposition of hydrocarbon in which purity of said carbon isotope 12C is not lower than 99.9 mass %, at a temperature not lower than 1500° C.
Polycrystalline diamond, comprising:
- carbon composed of any carbon isotope of 12C and 13C;
- and
- a plurality of impurities,
- the polycrystalline diamond having a concentration of each of said plurality of impurities not higher than 0.01 mass % and a crystal grain size not greater than 500 nm,
- the polycrystalline diamond having Knoop hardness not lower than 140 GPa, and
- the polycrystalline diamond fabricated by sintering graphite obtained by thermal decomposition of hydrocarbon in which purity of a carbon isotope 12C or 13C is not lower than 99.9 mass %, at a temperature not lower than 1500° C.
Dependencies are inferred from the claim text.