Sumitomo Electric Hardmetal Corp.

Sumitomo Electric Industries, Limited

Machiko Abe

Satoru Kukino

Kazuya Yano

Hiroyuki Shimada

Michiko Matsukawa

Katsumi Okamura

Akihiko Ueda

Taisuke Higashi

Hironari Moroguchi

Yoshinori Tanigawa

Takashi Harada

Akito Ishii

Mayuka Segawa

Kenta Sano

Kento Yamada

A drill includes a blade tip part that is formed of diamond and a trunk part that is formed of diamond and is continuous with the blade tip part, the drill rotating about a drill axis, the blade tip part includes N cutting edges where N is an integer of no less than 4, and a proportion of Sto Sis no less than 30% and no more than 60%, where Sis an area of the drill in a cross-section with the drill axis as a normal line, the cross-section including a boundary between the blade tip part and the trunk part, r is a maximum value of a distance from the drill axis to an outer edge of the drill in the cross-section and Sis an area of a circle with r as a radius.

Drill

A cubic boron nitride sintered material comprising cubic boron nitride grains, a binder phase, and a void, in which a percentage of the cubic boron nitride grains based on the total of the cubic boron nitride grains and the binder phase is 40 vol % to 70 vol %, a percentage of the binder phase based on the total of the cubic boron nitride grains and the binder phase is 30 vol % to 60 vol %, the binder phase includes 10 vol % to 100 vol % of aluminum oxide grains, an average grain size of the aluminum oxide grains is 50 to 250 nm, the cubic boron nitride sintered material comprises 0.001 vol % to 0.100 vol % of one or more first voids, and at least one portion of each of the first voids is in contact with the aluminum oxide grains.

Cubic boron nitride sintered material

Cutting edge for drilling tool

A cubic boron nitride sintered material includes 40% by volume or more and 96% by volume or less of cubic boron nitride grains and 4% by volume or more and 60% by volume or less of a binder phase, and the cubic boron nitride grains have a dislocation density of less than 1&#xd7;10/m.

Cubic boron nitride sintered material and method for manufacturing the same

A polycrystalline cubic boron nitride comprising 96% by volume or more of cubic boron nitride, wherein the cubic boron nitride has a dislocation density of more than 8&#xd7;10/m, 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 less than 100 nm.

Polycrystalline cubic boron nitride and method for manufacturing the same

A polycrystalline cubic boron nitride comprising 98.5% by volume or more of cubic boron nitride, wherein the cubic boron nitride has a dislocation density of more than 8&#xd7;10/m, 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 0.1 &#x3bc;m or more and 0.5 &#x3bc;m or less.

A polycrystalline cubic boron nitride comprising 96% by volume or more of cubic boron nitride, wherein the cubic boron nitride has a dislocation density of 8&#xd7;10/mor less, 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 less than 100 nm.

A cubic boron nitride sintered material comprises 30% by volume or more and 80% by volume or less of cubic boron nitride grains and 20% by volume or more and 70% by volume or less of a binder phase, the cubic boron nitride grains having a dislocation density of 3&#xd7;10/mor more and 1&#xd7;10/mor less.

Drilling tool

A cubic boron nitride sintered body tool has, at least at a cutting edge, a cubic boron nitride sintered body composed of a cubic boron nitride particle and a binder phase. The binder phase contains at least AlOand a Zr compound. On any straight line in the sintered body, the mean value of a continuous distance occupied by AlOis 0.1-1.0 &#x3bc;m, and the standard deviation of the continuous distance occupied by AlOis not more than 0.8. On the straight line, X/Y is 0.1-1 where X represents the number of points of contact between AlOand the Zr compound, and Y represents the sum of the number of points of contact between AlOand cBN and the number of points of contact between AlOand binder phase component(s) other than AlOand the Zr compound.

Growing community of inventors

Itami, Japan

Machiko Abe