Abstract: [Problem] This invention aims to provide a production method of a fine grain polycrystalline diamond compact which is suitable for finishing cutting tool materials and/or ultra-precision machining tool materials. In the method, a freeze-drying process for preventing the growth of secondary particle formation is unnecessary, and an aid does not need to be mixed in advance. [Means for Resolution] Disclosed is a following production method of a fine grain polycrystalline diamond compact. Each of carbonate and a C—H based organic compound which is a solid at room temperature, is sandwiched between diamond powder layers to stack them up in layers in a Ta capsule. Particle size of the diamond powder is 4 ?m or less in average; and the organic compound is preferably one or more selected from among polyethylene, polypropylene and polystyrene. The layers in the capsule are sintered under the conditions of a pressure of 7.7 GPa or higher and a temperature of 2000° C. or higher.

Abstract: A method for producing a highly uniform and highly dense sintered cubic boron nitride compact having high hardness by sintering at a milder condition without a binder, is provided. The method includes deflocculating secondary particles in cubic boron nitride starting powders by dispersing the starting powders in a solution of a deflocculant; molding the green compact after removing the solution of the deflocculant from the starting powders; and then sintering the green compact in the presence of a supercritical fluid source in a supercritical state by pressing and heating the green compact together with the supercritical fluid source. The supercritical fluid source can be one or more selected from a group consisted of polyvinylidene chloride, polyvinyl chloride, polyethylene, polypropylene, polystyrene, a polyester and an ABS resin. In the sintering, the pressure is 5 GPa or higher, and the temperature is 1400° C. or higher.

Abstract: [Problem] This invention aims to provide a production method of a fine grain polycrystalline diamond compact which is suitable for finishing cutting tool materials and/or ultra-precision machining tool materials. In the method, a freeze-drying process for preventing the growth of secondary particle formation is unnecessary, and an aid does not need to be mixed in advance. [Means for Resolution] Disclosed is a following production method of a fine grain polycrystalline diamond compact. Each of carbonate and a C—H based organic compound which is a solid at room temperature, is sandwiched between diamond powder layers to stack them up in layers in a Ta capsule. Particle size of the diamond powder is 4 ?m or less in average; and the organic compound is preferably one or more selected from among polyethylene, polypropylene and polystyrene. The layers in the capsule are sintered under the conditions of a pressure of 7.7 GPa or higher and a temperature of 2000° C. or higher.

Abstract: A method for producing a highly uniform and highly dense sintered cubic boron nitride compact having high hardness by sintering at a milder condition without a binder, is provided. The method includes deflocculating secondary particles in cubic boron nitride starting powders by dispersing the starting powders in a solution of a deflocculant; molding the green compact after removing the solution of the deflocculant from the starting powders; and then sintering the green compact in the presence of a supercritical fluid source in a supercritical state by pressing and heating the green compact together with the supercritical fluid source. The supercritical fluid source can be one or more selected from a group consisted of polyvinylidene chloride, polyvinyl chloride, polyethylene, polypropylene, polystyrene, a polyester and an ABS resin. In the sintering, the pressure is 5 GPa or higher, and the temperature is 1400° C. or higher.

Abstract: A cutting tool made of a surface-coated cubic boron nitride-based ultra-high-pressure sintered material, comprising a cutting insert main body formed by ultra-high-pressure sintering of a compact composed of titanium nitride, aluminum and/or aluminum oxide, and boron nitride, and a hard coating layer vapor deposited on the main body. The main body has a texture containing cubic boron nitride, titanium nitride and reaction product. The hard coating layer has a lower layer of nitride having a composition of [Ti1 -X-YAlXSiY]N, where X is in a range from 0.40 to 0.60 and Y is in a range from 0.02 to 0.10 in an atomic ratio, and the upper layer comprises a thin layer A having the composition of [Ti1-X-YAlXSiY]N, where X is in a range from 0.40 to 0.60 in an atomic ratio and Y is in a range from 0.02 to 0.10, and a thin layer B consisting of a Ti nitride (TiN). The upper layer consists of the thin layer A and a thin layer B layered alternately.

Abstract: A cutting tool made of a surface-coated cubic boron nitride-based ultra-high-pressure sintered material, comprising a cutting insert main body formed by ultra-high-pressure sintering of a compact composed of titanium nitride, aluminum and/or aluminum oxide, and boron nitride, and a hard coating layer vapor deposited on the main body. The main body has a texture containing cubic boron nitride, titanium nitride and reaction product. The hard coating layer has a lower layer of nitride having a composition of [Ti1-X-YAlXSiY]N, where X is in a range from 0.40 to 0.60 and Y is in a range from 0.02 to 0.10 in an atomic ratio, and the upper layer comprises a thin layer A having the composition of [Ti1-X-YAlXSiY]N, where X is in a range from 0.40 to 0.60 in an atomic ratio and Y is in a range from 0.02 to 0.10, and a thin layer B consisting of a Ti nitride (TiN). The upper layer consists of the thin layer A and a thin layer B layered alternately.

Abstract: A cutting insert exhibiting excellent chipping resistance made of cubic boron nitride based ultra-high pressure sintered material.

Abstract: A cutting insert exhibiting excellent chipping resistance made of cubic boron nitride based ultra-high pressure sintered material.

Abstract: A wear resistant C-BN-based cutting tool superior in toughness includes a specified amount of at least one of a Ti carbide/nitride component, a compound including at least one of Ti and Al, tungsten carbide, Al.sub.2 O.sub.3, and the balance being C-BN and incidental impurities.