Sumitomo Electric Industries, Limited

Sumitomo Electric Hardmetal Corp.

Yuh Ishida

Hitoshi Sumiya

Katsuko Yamamoto

Satoru Kukino

Keiko Arimoto

Kensei Hamaki

Katsumi Okamura

Akito Ishii

Takeshi Sato

Michiko Matsukawa

Hisaya Hama

Issei Nagashima

A polycrystalline cubic boron nitride includes a cubic boron nitride particle group. The ratio of a second length to a first length is 0.99 or less. Here, each of the first length and the second length is a value measured on a surface of the polycrystalline cubic boron nitride with an indentation formed by a Knoop hardness test under conditions specified in ISO4545-1 and ISO4545-4. The second length represents the length of the longer diagonal of the indentation. The first length represents the sum of the second length and the length of the streaky indentation.

Polycrystalline cubic crystal boron nitride and tool

A polycrystalline cubic boron nitride comprising 99.5% by volume or more of cubic boron nitride, wherein the polycrystalline cubic boron nitride has a heat conductivity of 300 W/mK or more, the polycrystalline cubic boron nitride has a carbon content of 100 ppm or more and 1000 ppm or less in terms of mass, the polycrystalline cubic boron nitride comprises a plurality of crystal grains, and the plurality of crystal grains have a median diameter d50 of an equivalent circle diameter of 0.9 μm or more and 10 μm or less.

Polycrystalline cubic boron nitride and heatsink using the same

A cubic boron nitride sintered material includes: more than or equal to 80 volume % and less than or equal to 96 volume % of cubic boron nitride grains; and a binder, wherein the binder includes tungsten carbide, cobalt, and an aluminum compound, and Ha/Hb&#x2265;0.40 is satisfied, where Hb represents a hardness of the cubic boron nitride sintered material and Ha represents a hardness of the cubic boron nitride sintered material after performing acid treatment onto the cubic boron nitride sintered material to substantially remove the binder in the cubic boron nitride sintered material.

Cubic boron nitride sintered material

A diamond polycrystal is a diamond polycrystal basically composed of a diamond single phase, wherein the diamond polycrystal is composed of a plurality of diamond grains having an average grain size of less than or equal to 30 nm, and the diamond polycrystal has a carbon dangling bond density of more than or equal to 10 ppm.

Diamond polycrystal and method of producing the same

A method of producing a boron nitride polycrystal includes: a first step of obtaining a thermally treated powder by thermally treating a powder of a high pressure phase boron nitride at more than or equal to 1300&#xb0; C.; and a second step of obtaining a boron nitride polycrystal by sintering the thermally treated powder under a condition of 8 to 20 GPa and 1200 to 2300&#xb0; C.

Method of producing boron nitride polycrystal, boron nitride polycrystal, cutting tool, wear-resisting tool, and grinding tool

Provided is a method for producing a polycrystalline diamond body, the method including a first step of heat-treating a powder of high-pressure-phase carbon at higher than or equal to 1300&#xb0; C. to obtain a heat-treated carbon powder, and a second step of sintering the heat-treated carbon powder under conditions of greater than or equal to 12 GPa and less than or equal to 25 GPa and higher than or equal to 1200&#xb0; C. and lower than or equal to 2300&#xb0; C. to obtain a polycrystalline diamond body.

Method for producing polycrystalline diamond body, polycrystalline diamond body, cutting tool, wear-resistance tool and grinding tool

A composite sintered material includes: cubic boron nitride grains; and hexagonal boron nitride grains or the hexagonal boron nitride grains and wurtzite type boron nitride grains, wherein a dislocation density of the cubic boron nitride grains is more than or equal to 1&#xd7;10/mand less than or equal to 1&#xd7;10/m, a median diameter d50 of equivalent circle diameters of the cubic boron nitride grains is more than or equal to 10 nm and less than or equal to 500 nm, and a relationship of the following expression 1 is satisfied:0.015&#x2264;()/()&#x2264;0.5,&#x2003;&#x2003;Expression 1:where Vc represents a volume-based content ratio of the cubic boron nitride grains, Vh represents a volume-based content ratio of the hexagonal boron nitride grains, and Vw represents a volume-based content ratio of the wurtzite type boron nitride grains.

Composite sintered material and tool using same

An indenter is made of polycrystalline diamond and has a tip having a spherical surface with a radius of 10 to 2000 &#x3bc;m.

Indenter made of polycrystalline diamond, and method and apparatus using the same for evaluating crack initiation load

A composite polycrystal includes: a polycrystalline diamond phase including a plurality of diamond particles; and non-diamond phases composed of non-diamond carbon. The non-diamond phases are distributed in the polycrystalline diamond phase. An average value of projected area equivalent circle diameters of the non-diamond phases is not more than 1000 nm.

Composite polycrystal and method for manufacturing the same

It is an object to provide a cubic boron nitride polycrystalline material excellent in toughness. A cubic boron nitride polycrystalline material containing fine cubic boron nitride which is granular, has a maximum grain size not greater than 100 nm, and has an average grain size not greater than 70 nm and at least one of plate-shaped cubic boron nitride in a form of a plate having an average major radius not smaller than 50 nm and not greater than 10000 nm and coarse cubic boron nitride which is granular, has a minimum grain size exceeding 100 nm, and has an average grain size not greater than 1000 nm is provided.

Cubic boron nitride polycrystalline material, cutting tool, wear resistant tool, grinding tool, and method of manufacturing cubic boron nitride polycrystalline material

A cubic boron nitride polycrystal includes cubic boron nitride, the cubic boron nitride having an average grain size of not more than 150 nm, the cubic boron nitride polycrystal having a crack generation load of not less than 25 N in a breaking strength test in which an R200 &#x3bc;m diamond indenter is used to apply a load at a rate of 100 N/min.

Cubic boron nitride polycrystal, cutting tool, wear-resistant tool, grinding tool, and method of producing cubic boron nitride polycrystal

A polycrystalline diamond body contains diamond particles, the diamond particles have a mean particle size of 50 nm or less, and a crack initiation load is 10 N or more as measured in a fracture strength test by pressing a diamond indenter D with a tip radius Dr of 50 &#x3bc;m against a surface of the polycrystalline diamond body at a load rate F of 100 N/min. Accordingly, a polycrystalline diamond body that is tough and has a small diamond particle size, a cutting tool, a wear-resistant tool, a grinding tool, and a method for producing the polycrystalline diamond body are provided.

Polycrystalline diamond body, cutting tool, wear-resistant tool, grinding tool, and method for producing polycrystalline diamond body

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&#xb0; C.&#xb1;5&#xb0; 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.

A cubic boron nitride complex polycrystal contains granular cubic boron nitride and tabular cubic boron nitride. The average grain size of the granular cubic boron nitride is 500 nm or less. The maximum value of a short side of the tabular cubic boron nitride is 10 nm or more to 10000 nm or less. Thereby, it is possible to provide a cubic boron nitride complex polycrystal having high hardness and a manufacturing method therefor, a cutting tool, a wire-drawing die and a grinding tool including the same.

Growing community of inventors

Itami, Japan

Yuh Ishida