Sumitomo Electric Industries, Limited

Akio Hara

Shuji Yazu

Masaya Miyake

Takaharu Yamamoto

Minol Nakano

Tetsuo Nakai

Tsuyoshi Asai

Kazuo Tsuji

Mitsuo Kodama

Toshio Nomura

Mitsunori Kobayashi

Yoshikatsu Mori

Hiroshi Fujii

Naoji Fujimori

Nobuhito Kuroishi

Masaaki Tobioka

Mitsuhiro Goto

Mitsuo Osada

Yuichiro Kohno

Akihiko Yamamura

Noriyuki Ayano

Takeshi Asai

Yuichiro Kono

A sintered diamond compact or high pressure form boron nitride compact with an improved brazability, suitable for use for wear resisting tools, cutting tools, drill bits, dressers and wire-drawing dies is provided. This compact comprises a compact part containing at least 20% by volume of diamond and/or high pressure form boron nitride and a cemented carbide substrate bonded directly or through an interlayer to the compact part, characterized in that the surface of the compact is coated, at least partly, with a thin film consisting essentially of at least one member selected from the group consisting of carbides, carbonitrides and nitrides and mixtures or solid solutions thereof of at least one element selected from the group consisting of silicon and Group IVa, Va and VIa of Periodic Table, and having a thickness of 1 to 20 .mu.m.

Hard sintered compact for a tool

A composite tool with a higher bonding strength and higher heat resistance is provided comprising an insert of a hard material such as composite diamond or BN compacts and a support of a hard metal or alloy such as steel and cemented carbides, having a larger volume than the insert, the insert and support being bonded by friction welding through an interlayer of a high strength metal or alloy such as Co and Ni with a thickness of at most 1 mm.

Composite tool and a process for the production of the same

Process for the production of a composite tool

A stick of composite materials comprises a hot-pressed super-hard head member containing higher than 50 vol % of a diamond powder and/or a high pressure boron nitride powder, and a supporting member which is bonded at one of its ends with the hot-pressed super-hard head member. The stick of composite materials is characterized in that:

Stick of composite materials and process for preparation thereof

A composite sintered material suitably used as a material for a drill has a sandwich structure comprising a hard layer of a sintered diamond compact including an iron group metal sandwiched between a pair of substrates and intermediate layers. The pair of intermediate layers each has a thickness of 10 to 500 microns. The intermediate layers are bonded respectively to one of the opposite surfaces of the hard layer, with each of the intermediate layers comprising a material which has a thermal expansion coefficient of 3.0.times.10.sup.-6 to 6.0.times.10.sup.-6 /.degree.C. and which prevent the transfer of the iron group metal therethrough in the course of sintering of the hard material. The pair of substrates are bonded respectively to one of the surfaces of the intermediate layers to form a sandwich construction with the hard layer. The substrates comprise a metal or alloy having a thermal expansion coefficient lower than 6.0.times.10.sup.-6 /.degree.C. In using the composite sintered material as a blade tip for a cutting tool, the sintered diamond compact contains preferably 5 to 15 vol. % of an iron group metal, the balance being of diamond particles, and each of the substrates is composed of a sintered alloy mainly composed of WC and/or MOC having a thermal expansion coefficient lower than 4.6.times.10.sup.-6 /.degree.C.

Composite sintered material having sandwich structure

A process for producing a cutting tool having a rake face and flank face which intersect to form a cutting edge, which cutting tool comprises a substrate consisting of a sintered hard metal and a coating film provided thereon consisting of a material with a higher hardness than the substrate, which method involves subjecting the substrate to a coating treatment and honing treatment in such a manner that the coating film near the cutting edge has such a thickness that the thickness continuously increases in directions away from the cutting edge along both the rake face and the flank face from a minimum value, including zero, at the cutting edge, such that the thickness of the coating at the rake face reaches a maximum thickness at a first distance from the cutting edge and the thickness at the flank face reaches a maximum thickness at a second distance from the cutting edge, wherein the first distance is greater than the second distance.

Process for the production of a cutting tool

A cutting insert having excellent toughness as well as wear resistance is provided comprising a substrate consisting of a sintered hard metal or alloy such as cemented carbides and a coating film provided thereon consisting of a material having a higher hardness than the substrate, characterized in that the coating film near the cutting edge is continuously made thinner or removed toward both the rake face and flank face.

Coated hard metal tool

This invention relates to a hard alloy comprising two phases: a hard phase consisting of at least one compound having a crystal structure of simple hexagonal MC type (M: metal; C: carbon) selected from the group consisting of mixed carbides, carbonitrides and carboxynitrides of molybdenum and tungsten, and a binder phase consisting of at least one element selected from the group consisting of iron, cobalt and nickel. The hard phase is prepared by carburizing an (Mo, W) alloy obtained by reducing oxides of molybdenum and tungsten with a particle size of at most 1 micron, is composed of coarse particles with a mean particle size of at least 3 microns, and has a uniform molybdenum to tungsten ratio in the particles. The hard alloy has a gross composition within the range of the shaded portion ABCDEA in FIG. 1.

Hard alloy containing molybdenum

A method for producing a sintered ferrous alloy containing at least one alloying element whose standard free energy for oxide formation at 1,000.degree. C. is 11,000 cal/g mol O.sub.2 or less is described. The method comprises a sintering procedure comprising steps of elevating the temperature of a green compact comprising said at least one alloying element, sintering it in a sintering furnace and cooling it, wherein the pressure in the sintering furnace is maintained at between about 0.2 and 500 Torr by supplying a reducing gas during at least a part of the sintering procedure under reduced pressure.

Process for producing sintered ferrous alloys

Process for the production of bonded hard alloys, which comprises inserting a thin sheet of a Fe group metal or its alloy as a filler in between the surfaces of at least one kind of hard alloy, and applying a high energy beam to a part or all of the thin sheet to melt and solidify the thin sheet in a slit form, thereby bonding the hard alloys together.

Process for the production of bonded hard alloys

The invention relates to a sintered body for use in a cutting tool comprising a cutting edge forming part having particularly high hardness and wear resistance bonded to a supporting member having high plastic deformability, stiffness, transverse rupture strength, thermal conductivity, thermal expansion coefficient, resistance to corrosion, oxidization and the like, and to a method for producing the same. A diamond powder or high pressure form boron nitride powder is placed in contact with preliminarily sintered cermet constituted by carbide crystals chiefly comprising molibdenum in the form of (Mo, W)C bonded by iron group metals, the combined body being sintered at a temperature and pressure under which the diamond powder or high pressure form boron nitride powder is thermodynamically stable so that the sintered body of the diamond or high pressure form boron nitride is bonded to the cermet thereby enabling to obtain a sintered body having the said high properties for use in a cutting tool.

Sintered body for use in a cutting tool and the method for producing the

The invention relates to a diamond sintered compact wherein diamond crystal particles are uniformly orientated in a particular direction and the method for producing the same, and has for an object to provide a diamond sintered compact having a high thermal conductivity particularly suitable for heat sink for use in the field of electronics. According to the invention, graphite is used as carbonaceous raw material, diamond crystal particles having such elongated shape that the ratio of the length of the long axis to that of the short axis is more than 2 being synthesized in such state that the greater part of the crystal particles have their long axes uniformly oriented in a particular direction, the crystal particles being sintered in the direction of the long axes thereof so that transformation of the graphite into diamond and sintering thereof may be accomplished synchronously. The invention has for an object to obtain a diamond sintered compact suitable for the aforesaid use by degassing reaction system raw material plugged into an air permeable container by heating it in vacuum in order to intercept gaseous components causing a decrease of thermal conductivity at the time of synthesizing diamond from carbonaceous material and a catalytic metal and sintering thereof, subsequently the air permeable part of the said container being sealed by means of soldering material preliminarily placed in contact with the said container.

Diamond sintered compact wherein crystal particles are uniformly

The invention relates to a diamond sintered compact wherein diamond crystal particles are uniformly oriented in a particular direction and the method for producing the same, and has for an object to provide a diamond sintered compact having a high thermal conductivity particularly suitable for heat sink for use in the field of electronics. According to the invention, graphite is used as carbonaceous raw material, diamond crystal particles having such elongated shape that the ratio of the length of the long axis to that of the short axis is more than 2 being synthesized in such state that the greater part of the crystal particles have their long axes uniformly oriented in a particular direction, the crystal particles being sintered in the direction of the long axes thereof so that transformation of the graphite into diamond and sintering thereof may be accomplished synchronously. The invention has for an object to obtain a diamond sintered compact suitable for the aforesaid use by degassing reaction system raw material plugged into an air permeable container by heating it in vacuum in order to intercept gaseous components causing a decrease of thermal conductivity at the time of synthesizing diamond from carbonaceous material and a catalytic metal and sintering thereof, subsequently the air permeable part of the said container being sealed by means of soldering material preliminarily placed in contact with the said container.

Method for producing a diamond sintered compact

The invention enables to obtain a compound sintered compact for use in a cutting tool having particularly high properties in respect of bonded strength, hardness, wear resistance, plastic deformability and rigidity by bonding a diamond or cubic boron nitride containing hard layer to a cemented carbide substrate with interposition of an intermediate bonding layer. A powder for forming the intermediate bonding layer comprising cubic boron nitride in an amount less than 70 volume %, the residual part principally consisting of a compound selected from among carbides, nitrides, carbonitrides or borides of 4a, 5a, 6a transition metals of the periodic table, an admixture thereof, or a mutual solid solution compound thereof, after pressing or in the state of powder, is placed on the cemented carbide substrate to a thickness less than 2 mm, or preliminarily applied to said cemented carbide substrate, further on said powder being placed a powder for forming the hard sintered compact containing diamond or cubic boron nitride in an amount in excess of 20 volume % after pressing or in the state of powder, the whole being hot pressed under an ultrahigh pressure and a high temperature to sinter the diamond or cubic boron nitride containing hard layer and the intermediate layer as well as to bond said hard layer, intermediate layer and substrate to each other, thereby enabling to obtain a compound sintered compact having the aforesaid superior properties for use in a cutting tool.

Compound sintered compact for use in a tool and the method for producing

The invention relates to a sintered compact for use in an ultrahard tool having high resistance to heat and wear, outstanding thermal conductivity and thermal shock resistance property at elevated temperature, and suitable for high-speed cutting, and to a method for producing the same. A powder mixture comprising 20-80 volume % high pressure form boron nitride powder, the residual part consisting of Al.sub.2 O.sub.3 powder or a compound ceramic powder principally comprising Al.sub.2 O.sub.3 powder and also containing carbides, nitrides of IVb, Vb, VIb metals of the periodic table, mutual solid solution thereof or admixture thereof, is sintered as it stands or after pressing under a high pressure and a high temperature so that Al.sub.2 O.sub.3 of the compound ceramic constitutes a continuous phase in the structure of the sintered compact, and the half width of (116) in the X-ray diffraction of CuK.alpha. ray of Al.sub.2 O.sub.3 crystals in the structure constituting the continuous phase is within the range from 0.200 deg. to 0.600 deg., thereby enabling to obtain a sintered compact for use in a tool having the aforesaid high properties.

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Itami, Japan

Akio Hara