Abstract: A polycrystalline diamond body contains diamond particles. The diamond particles have a mean particle size of 50 nm or less. As a result of measurement of a knoop hardness under a test load of 4.9 N at 23° C.±5° C., the polycrystalline diamond body has a ratio of a length B of a shorter diagonal line with respect to a length A of a longer diagonal line of diagonal lines of a knoop indentation, expressed as a B/A ratio, of 0.080 or less. This polycrystalline diamond body is tough and has a small particle size.

Abstract: Provided are a diamond polycrystalline body having a longer life than conventional diamond polycrystalline bodies when it is slid, a method for manufacturing the same, and a tool. In a diamond polycrystalline body, at least one element whose sulfide or chloride has a melting point of less than or equal to 1000° C. is added thereto, and crystal grains have an average grain size of less than or equal to 500 nm. Thereby, wear of diamond can be suppressed, and the diamond polycrystalline body can have a longer life when it is slid.

Abstract: Provided are a diamond polycrystalline body having a longer life than conventional diamond polycrystalline bodies when it is slid, a method for manufacturing the same, and a tool. In a diamond polycrystalline body, at least one element whose oxide has a melting point of less than or equal to 1000° C. is added thereto, and crystal grains have an average grain size of less than or equal to 500 nm. Thereby, wear of diamond can be suppressed, and the diamond polycrystalline body can have a longer life when it is slid.

Abstract: A cubic boron nitride polycrystal includes cubic boron nitride, the cubic boron nitride having an average grain size of not more than 150 nm, a ratio b/a being not more than 0.085 in measurement of Knoop hardness at 23° C.±5° C. under a test load of 4.9 N, the ratio b/a being a ratio between a length a of a longer diagonal line and a length b of a shorter diagonal line of a Knoop indentation.

Abstract: An object is to provide polycrystalline diamond applicable to diverse applications; and a water jet orifice, a stylus for gravure printing, a scriber, a diamond cutting tool, and a scribing wheel that include such polycrystalline diamond. This object is achieved by polycrystalline diamond obtained by converting and sintering non-diamond carbon under an ultrahigh pressure and at a high temperature without addition of a sintering aid or a catalyst, wherein sintered diamond grains constituting the polycrystalline diamond have an average grain diameter of more than 50 nm and less than 2500 nm and a purity of 99% or more, and the diamond has a D90 grain diameter of (average grain diameter+average grain diameter×0.9) or less.

Abstract: Polycrystalline diamond includes cubic diamond and hexagonal diamond, and a ratio of X-ray diffraction peak intensity of a (100) plane of the hexagonal diamond to X-ray diffraction peak intensity for a (111) plane of cubic diamond is not lower than 0.01%. In addition, a present method of manufacturing polycrystalline diamond includes the steps of preparing a non-diamond carbon material having a degree of graphitization not higher than 0.58 and directly converting the non-diamond carbon material to cubic diamond and hexagonal diamond and sintering the non-diamond carbon material, without adding any of a sintering agent and a binder, under pressure and temperature conditions at which diamond is thermodynamically stable.

Abstract: Nano polycrystalline diamond is composed of carbon, an element of different type which is an element other than carbon and is added to be dispersed in carbon at an atomic level, and an inevitable impurity. The polycrystalline diamond has a crystal grain size not greater than 500 nm. The polycrystalline diamond can be fabricated by subjecting graphite in which the element of different type which is an element other than carbon has been added to be dispersed in carbon at an atomic level to heat treatment within high-pressure press equipment.

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.

Abstract: Polycrystalline diamond includes cubic diamond and hexagonal diamond, and a ratio of X-ray diffraction peak intensity of a (100) plane of the hexagonal diamond to X-ray diffraction peak intensity for a (111) plane of cubic diamond is not lower than 0.01%. In addition, a present method of manufacturing polycrystalline diamond includes the steps of preparing a non-diamond carbon material having a degree of graphitization not higher than 0.58 and directly converting the non-diamond carbon material to cubic diamond and hexagonal diamond and sintering the non-diamond carbon material, without adding any of a sintering agent and a binder, under pressure and temperature conditions at which diamond is thermodynamically stable.

Abstract: Provided is a technology for manufacturing cutting tools that is capable of providing cutting tools that have a cut surface whose surface is uniformly smooth and that have a stable performance.

Abstract: The present invention provides a cutting tool that achieves cutting with high precision. The cutting tool of the present invention includes a cutting edge composed of a polycrystalline body including high-pressure-phase hard grains that contain one or more elements selected from the group consisting of boron, carbon, and nitrogen, the polycrystalline body being formed by subjecting a non-diamond carbon material and/or boron nitride, serving as a starting material, to direct conversion sintering under ultra-high pressure and high temperature without adding a sintering aid or a catalyst, in which letting the radius of curvature of the nose of the cutting edge of the cutting tool be R1, the sintered grains constituting the polycrystalline body have an average grain size of 1.2×R1 or less and a maximum grain size of 2×R1 or less.

Abstract: Polycrystalline diamond includes cubic diamond and hexagonal diamond, and a ratio of X-ray diffraction peak intensity of a (100) plane of the hexagonal diamond to X-ray diffraction peak intensity for a (111) plane of cubic diamond is not lower than 0.01%. In addition, a present method of manufacturing polycrystalline diamond includes the steps of preparing a non-diamond carbon material having a degree of graphitization not higher than 0.58 and directly converting the non-diamond carbon material to cubic diamond and hexagonal diamond and sintering the non-diamond carbon material, without adding any of a sintering agent and a binder, under pressure and temperature conditions at which diamond is thermodynamically stable.

Abstract: The composite sintered body of the invention is a composite sintered body, containing 20 volume % or more and 80 volume % or less of cubic boron nitride particles, and a binder; wherein the binder contains at least one selected from the group consisting of nitrides, carbides, borides, and oxides of elements in the group 4a, elements in the group 5a, and elements in the group 6a in the periodic table, and solid solutions thereof, at least one selected from the group consisting of simple substances of Zr, Si, Hf, Ge, W and Co, compounds thereof, and solid solutions thereof, and a compound of Al; and when the composite sintered body contains therein W and/or Co, the total weight of the W and/or Co is less than 2.0 weight % and further the composite sintered body contains therein one or more of the Zr, Si, Hf and Ge (hereinafter referred to as “X”), and when the composite sintered body contains the X, the amount of each of the X is 0.005 weight % or more and less than 2.0 weight %, X/(X+W+Co) is 0.

Abstract: An object is to provide polycrystalline diamond applicable to diverse applications; and a water jet orifice, a stylus for gravure printing, a scriber, a diamond cutting tool, and a scribing wheel that include such polycrystalline diamond. This object is achieved by polycrystalline diamond obtained by converting and sintering non-diamond carbon under an ultrahigh pressure and at a high temperature without addition of a sintering aid or a catalyst, wherein sintered diamond grains constituting the polycrystalline diamond have an average grain diameter of more than 50 nm and less than 2500 nm and a purity of 99% or more, and the diamond has a D90 grain diameter of (average grain diameter+average grain diameter×0.9) or less.

Abstract: The composite sintered body of the invention is a composite sintered body, containing 20 volume % or more and 80 volume % or less of cubic boron nitride particles, and a binder; wherein the binder contains at least one selected from the group consisting of nitrides, carbides, borides, and oxides of elements in the group 4a, elements in the group 5a, and elements in the group 6a in the periodic table, and solid solutions thereof, at least one selected from the group consisting of simple substances of Zr, Si, Hf, Ge, W and Co, compounds thereof, and solid solutions thereof, and a compound of Al; and when the composite sintered body contains therein W and/or Co, the total weight of the W and/or Co is less than 2.0 weight % and further the composite sintered body contains therein one or more of the Zr, Si, Hf and Ge (hereinafter referred to as “X”), and when the composite sintered body contains the X, the amount of each of the X is 0.005 weight % or more and less than 2.0 weight %, X/(X+W+Co) is 0.

Abstract: A conductive polycrystalline diamond film having specific resistance of at least 1×10−4 &OHgr;cm and less than 1×103 &OHgr;cm, whose film thickness is in the range of at least 0.1 &mgr;m and not more than 500 &mgr;m, is film-formed by vapor-phase synthesis on a surface employed for pressure bonding, a surface opposite to this surface or at least two side surfaces intersecting with these surfaces on a substrate of a bonding tool tip that is applicable for bonding and packaging a semiconductor chip.