Sumitomo Electric Industries, Limited

Kobe Mechatronics Co., Ltd.

Ataka Construction & Engineering

Junichi Shiraishi

Tetsuo Nakai

Satoru Kukino

Tomohiro Fukaya

Katsuhito Yoshida

Yasunobu Ogata

Shinya Uesaka

Takashi Harada

Haruyo Fukui

Yasuyuki Kanada

Hisanori Ohara

Kenji Matsuura

Michiko Ota

Michinari Asano

A coated sintered body can be used for a cutting tool for precision machining of hardened steel. The coated PCBN cutting tool includes a substrate which contains not less than 35 volume % and not more than 85 volume % of CBN, and a hard coated layer formed on the substrate. The hard coated layer comprises at least one compound layer consisting of at least one element selected from the group 4a, 5a, and 6a elements of the periodic table and Al, and at least one element selected from C, N and O. The thickness of the layer is not less than 0.3 &mgr;m and not more than 10 &mgr;m. The center-line mean roughness of the hard coated layer is not more than 0.1 &mgr;m.

Coated PCBN cutting tools

A sintered material containing high-pressure phase-type boron nitride and a binder is provided. The high-pressure phase-type boron nitride is contained in an amount of from 50% to 78% by volume, and the balance is a binder phase. The binder phase comprises at least one selected from the group consisting of nitride, carbide, carbonitride, and boride of Ti, nitride, boride and oxide of Al, carbide and boride of W, nitride, carbide, carbonitride and boride of Co, and carbide and boride of Ni, or a mutual solid solution thereof. The binder phase forms a binder phase which is continuous in a sintered material texture. The weight of metal components Al, W, Co and Ni which are present as compounds in the sintered material is from 3% to 20% based on the sintered material. The sintered material is excellent in crater resistance and capable of realizing a long tool life, even under the condition that the temperature of the cutting edge becomes high and the impact is large, as in high-speed interrupted cutting of hardened steel where the cutting speed V becomes at least 150 m/min.

High strength sintered impact having excellent resistance to cratering

Polycrystal diamond tool

Diamond sintered compact and a process for the production of the same

A cutting tool according to the present invention is coated with one or more Al O layers on at least a part of the surface of a cBN-based sintered material substrate taking part in cutting. The sintered material substrate is made of cBN in an amount of from 20% to 99% by volume and Al O having an average crystalline particle diameter of not more than 1 &mgr;m in an amount of from not less than 1.0% to less than 10% by volume. The Al O layer has a thickness (d) of from 0.5 &mgr;m to 50 &mgr;m. The average crystalline particle diameter (s) of Al O is from 0.01 &mgr;m to 4 &mgr;m if the thickness (d) of the Al O layer is from 0.5 &mgr;m to 25 &mgr;m or from not less than 0.01 &mgr;m to not more than 10 &mgr;m if the thickness (d) of the Al O layer is from more than 25 &mgr;m to 50 &mgr;m.

Cutting tool made of A12O3-coated cBN-based sintered material

A cBN sintered body superior in chipping resistance. The cBN sintered body is a sintered body in which cBN particles are bonded through a bonding phase. The bonding phase has a two-dimensionally continuous structure. The bonding phase comprises at least one kind selected from the group consisting of (a) carbide, nitride, carbonitride, or boride of a 4a-, 5a-, or 6a-group transition metal in the periodic table; (b) nitride, boride, or oxide of Al; (c) at least one kind of carbide, nitride, carbonitride, and boride of Fe, Co, or Ni; and (d) a mutual solid solution of those. The percentage of cBN content is 45 to 70% in volume. The bonding phase has the thickness of which the average value is 1.5 &mgr;m or less and the standard deviation is 0.9 &mgr;m or less with the cBN particles having an average particle size of 2 to 6 &mgr;m inclusive. The bonding phase has the thickness of which the average value is 1.0 &mgr;m or less and the standard deviation is 0.7 &mgr;m or less with the cBN particles having an average particle size of not less than 0.01 &mgr;m and less than 2.0 &mgr;m.

Cubic boron nitride sintered body

A polycrystal diamond tool is provided whose heat resistance, strength and anti-adhesion property are improved by modifying the porosity of a diamond sintered compact and which comprises a diamond sintered compact, sintered under ultra-high pressure and high temperature, brazed onto a tool substrate, in which the cutting edge vicinity part consists of 85 to 99 volume % of the diamond sintered compact material consisting of diamond grains bonded with each other and the balance of pores, and the other part than the cutting edge vicinity part consists of diamond grains and the balance of a brazing material.

A sintered body contains a high pressure form boron nitride in the range of 20 to 70% by volume, a first binding material surrounding the high pressure form boron nitride with a thickness in the range of 5 nm to 300 nm and a second binding material of the balance. The first binding material is composed of at least one of nitride and boride of Ti and Al. The second binding material is composed of at least one selected from the group consisting of nitride, carbide, carbonitride, boride and oxide of Al and transition metals belonging to the group 4,, 5,and 6,in the periodic table and mutual solid solution thereof. Supposing that X is the amount of Al contained per unit volume in the first binding material and Y is the amount of Al contained per unit volume in the second binding material, the ratio X/Y is not less than 1.

High strength sintered body

A diamond sintered body having high wear resistance, chipping resistance, shock resistance and thermal conductivity is provided. The diamond sintered body includes sintered diamond particles and a sintering aid as the remainder. The content of the sintered diamond particles is at least 80% by volume and less than 99% by volume. The sintered diamond particles have a particle size in the range from at least 0.1 &mgr;m to at most 70 &mgr;m. The sintered diamond particles next to each other are directly bonded. The sintering aid includes at least one kind selected from tungsten, iron, cobalt and nickel. The percentage of the tungsten in the sintered body is in the range from at least 0.01% by weight to at most 8% by weight.

Diamond sintered body having high strength and high wear resistance, and tool including the same

A method of cutting hardened steel using a cBN sintered tool which can improve the surface roughness while maintaining high dimensional accuracy. The upper limit of the tool feed rate is set at such a value that a theoretical surface roughness calculated from the feed rate is between 2/3 and 1/1000 of the target surface roughness. The amount of change of the feed rate between the upper and lower limits of the tool feed rate is set to be between 0.002 and 0.05 mm/rev, and the amount of every feed rate change is set not to be equal to the original feed rate multiplied by an integer. The feed rate is changed forcibly for every number of workpieces for which the total cutting length is between 10 and 1000 meters.

Method of cutting hardened steel with high accuracy

High-pressure phase boron nitride base sinter

A sintered body consists of high-pressure phase boron nitride, a residual binder phase and an unavoidable impurity, and contains high-pressure phase boron nitride powder which is previously coated with a binder before sintering. The coating binder consists of an element belonging to the group 4a, 5a or 6a of the periodic table or the like, and has an average thickness of 5 to 300 nm. Binder powder other than the coating binder consists of an element belonging to the group 4a, 5a or 6a of the periodic table or the like, and a contact ratio of high-pressure phase boron nitride particles in surface-to-surface contact with each other is at least 20% and less than 50%. The resulting high-pressure phase boron nitride-based hard and tough sintered body for a cutting tool is improved in wear resistance and chipping resistance.

Growing community of inventors

Hyogo, Japan

Junichi Shiraishi