Sumitomo Electric Industries, Limited

Mitsuhiro Goto

Tetsuo Nakai

Satoru Kukino

Makoto Setoyama

Takashi Yoshioka

Katsumi Okamura

Tomohiro Fukaya

Michiko Matsukawa

Akio Hara

Kenichi Kikutani

It is an object of the invention to provide a tool for precision finishing and grooving of quenched steel by thinning a coating film of a CBN sintered compact tool. The invention provides a surface-coated high hardness material for tool comprising a cubic boron nitride sintered compact (CBN sintered compact, hereinafter) as a substrate and at least one coating film layer formed on the surface of the substrate wherein said coating film layer has thickness of 0.1 &#x3bc;m or more and less than 1 &#x3bc;m and comprises, as main component, a compound having at least one kind of element selected from C, N and O, and Ti and Al. If this material is used as a grooving tool, excellent performance is exhibited. Examples of the coating film are an intermediate layer, a wear-resistant film, a surface layer and the like.

Surface-coated high hardness material for tool

Super hard composite material for tools, comprising a substrate of CBN sintered body containing more than 20% by volume of cubic boron nitride (CBN), improved in strength of base material, wear-resistance, hardness at high temperatures and acid-resistance usable in cutting work of steels which are difficult to be machined. The substrate (2) has a laminated film (1) consisting of super thin films (a) and (b) each deposited alternatively on the substrate (2), the super thin film (a) being made of nitride and/or carbide of at least one element selected from a group comprising IVa group elements, Va group elements, VIa group elements, Al and B and possessing a crystal structure of cubic system and metallic bond property, the super thin film (b) being made of at least one compound possessing a crystal structure other than cubic system and covalent bond property under equilibrium condition at ambient temperature and pressure, each unit layer of the super thin films (a) and (b) having a thickness of 0.2 nm to 20 nm, and the laminated film (1) on the whole possessing a crystal structure of cubic system.

Super hard composite material for tools

Hard composite material for tools, comprising a substrate of CBN sintered body containing more than 20% by volume of cubic boron nitride or diamond sintered body containing more than 40% by volume of diamond. The substrate has at least one layer of hard heat-resisting film consisting mainly of Ti, Al and at least one element selected from a group comprising C, N and O on a portion or portions of said substrate where cutting participate. Improved in strength of base material, wear-resistance and oxidation-resistance, less reactive with iron and showing longer tool life comparing to known cutting tools and usable in wider applications such as hardened steel, cast ion and simultaneous cutting of cast ion and aluminum alloy.

Hard composite material for tools

A sintered body insert for cutting comprises an intermediate layer consisting of at least one of cemented carbide, a ferrous metal and a high melting point metal, and a first layer and a second layer, each consisting of hard sintered bodies containing cubic boron nitride or diamond, which are arranged on opposite sides respectively above and below with the intermediate layer therebetween. The first and second layers are bonded to the intermediate layer by sintering. The is so formed or configured that its front and rear surfaces define cutting faces. All noses and flanks involved in cutting are formed on the first layer and the second layer, while the centers of gravity of the cutting faces and of the overall insert are located at positions on or in the intermediate layer. Further, coating layers consisting of a nitride of an element belonging to the group 4a, 5a or 6a of the periodic table or other components are formed on the surfaces of the cutting faces and the flanks. With this structure, it is possible to provide a sintered body insert for cutting which is prolonged in life and excellent in economy such as the manufacturing cost.

Sintered body insert for cutting and method of manufacturing the same

Ultrafine particle-layered film for coating cutting tools. The film has more than two layers of at least two compounds consisting mainly of carbide, nitride, carbonitride or oxide of at least one element selected from a group consisting of IVa group elements, Va group elements, VIa group elements, Al, Si and B, and that each layer is made of ultrafine particles. Ultrafine particle-layered film improves hardness, strength, wear-resistance and heat-resistance of the tools.

Layered film made of ultrafine particles and a hard composite material

In this invention, a cutting tool comprises two layers of hard sintered compact of cBN. The first sintered compact layer comprises about 75-98% by volume of cBN and a first binder material. The first binder material comprises from about 1 to out 40% by weight of Al. The second sintered compact layer comprises from about 40 to about 65% by volume of cBN and a second binder material. The second binder material comprises about 2 to about 30% by weight of Al. The first sintered compact layer is bonded to the second sintered compact layer. This composite material is bonded directly or indirectly to a tool holder to form a cutting tool. The first sintered compact layer constitutes a rake face of the cutting tool.

Hard sintered compact for tools

In a hard sintered cutting tool, the tool life can be further increased. In this hard sintered body cutting tool, a rake face of an edge portion is formed by a major surface of a first sintered body layer containing at least 80 percent by volume and less than 98 percent by volume of diamond, while a flank of the edge portion is formed by a second sintered body layer containing at least 30 percent by volume and less than 75 percent by volume of cubic boron nitride (CBN). The first sintered body layer is formed to have a thickness of at least 0.02 mm and less than 0.1 mm, and to be in a thickness ratio of at least 1:5 to the second sintered body layer. Thus, chipping resistance of the rake face is improved by the first sintered body layer, while wear resistance of the flank is improved by the second sintered body layer. As a result, it is possible to suppress progress of local wear and chipping, whereby the life of the cutting tool is increased as compared with the prior art.

Hard sintered body cutting tool

A sintered body for high-accuracy working tools is obtained by sintering powder mixture containing at least 45 percent by volume and not more than 60 percent by volume of cubic boron nitride powder having an average particle size of not more than 2 .mu.m and having a remainder formed of binder powder under a superhigh pressure. The binder contains at least 5 percent by weight and not more than 15 percent by weight of Al and at least 2 percent by weight and not more than 20 percent by weight of W, and has a binder remainder formed of a Ti compound or compounds. The atomic ratio of Ti contained in the binder to a transition metal element or elements belonging to any of the groups IVa, Va and/or VIa of the periodic table including Ti is at least 2/3 and not more than 97/100. In the structure of the sintered body, cubic boron nitride crystals are bonded with each other through bonding phases formed by the binder. When at least one or more Ti compounds are selected from a group of TiN.sub.z, Ti(C.sub.1-x N.sub.x).sub.z, (Ti,M) (C.sub.1-x N.sub.x ).sub.z and (Ti,M)N.sub.z, where M represents transition metal element or elements belonging to any of the groups IVa, Va and/or VIa of the periodic table excluding wherein z is within the range 0.45.ltoreq.z.ltoreq.0.65 and x is within the range of 0.50.ltoreq.x&lt;1.0. A sintered body is obtained which is excellent in strength and improved in wear resistance and useful as a material for making high-accuracy cutting tools.

Sintered body for high-accuracy working tools

A hard sintered body for tools is obtained by sintering under a superhigh pressure, a sinter powder mixture containing at least 20 percent by volume and not more than 70 percent by volume of cubic boron nitride powder and having a remainder formed of a binder powder mixture. The binder contains at least 2 percent by weight and not more than 20 percent by weight of Al and at least 2 percent by weight and not more than 20 percent by weight of W, and has a remainder formed of a Ti compound or compounds. The atomic ratio of Ti contained in the binder to a transition metal element or elements belonging to any of the groups IVa, Va and/or VIa of the periodic table including Ti is at least 2/3 and not more than 97/100. In the structure of the sintered body, cubic boron nitride crystals are bonded with each other through bonding phases formed by the binder. For forming the sintered body, at least one or more Ti compounds are selected from a group of TiN.sub.z, Ti(C,N).sub.z, TiC.sub.z, (Ti,M)N.sub.z, (Ti, M) (C,N).sub.z and (Ti,M)C.sub.z, wherein M represents a transition metal element or elements belonging to any one of the groups IVa, Va and/or VIa of the periodic table excluding Ti, and z is within the range of 0.1.ltoreq.z.ltoreq.0.40. Such a sintered body has an excellent crater wear resistance, so that it can be used for making tool inserts for high-speed cutting of steel or cast iron.

Hard sintered body for tools

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 hard sintered compact for tools is a sintered compact obtained by super-high pressure sintering of 45-75% by vol. of cubic boron nitride powder and the remaining proportion of binder powder. The binder includes 5-25% by wt. of Al and the remaining proportion of at least one species of compounds represented by (Hf.sub.1-z M.sub.z) C, where M denotes elements of IVa, Va and VIa groups in a periodic table except for Hf, and 0.ltoreq.z.ltoreq.0.3 is satisfied. Because of this composition, improvements are made in strength, wear resistance and heat resisting property of the binder, and a hard sintered compact for tools having excellent strength and excellent wear resistance can be obtained.

A sintered compact is obtained by sintering a mixture containing about 50 to 75 percent by volume of cubic boron nitride and about 25 to 50 percent of a binder under cBN-stable superhigh pressure conditions. The binder contains about 20 to 50 percent by weight of Al and one or more Ti compounds selected from the group consisting of TiN.sub.z, Ti(C,N).sub.z, TiC.sub.2, (Ti,M)C.sub.z, (Ti,M) (C,N).sub.z and (Ti,M)N.sub.z, wherein M indicates a transition metal of the group IVa, Va or VIa of the periodic table excepting Ti, and wherein z is within a range of 0.5.ltoreq.z.ltoreq.0.85. The atomic ratio of the content of Ti to that of the transition metal M in the binder is within the range of about

A cBN sintered compact for an end mill obtained by sintering mixed powder prepared by mixing about 35 to 50 percent by volume of cubic boron nitride powder smaller than about 2 .mu.m in average particle size with about 50 to 65 percent by volume of a binder under cBN-stable superhigh pressure conditions. The binder contains about 20 to 30 percent by weight of Al and one or more Ti compounds selected from a group of TiN.sub.z, Ti(C,N).sub.z, TiC.sub.z, (Ti,M)C.sub.z, (Ti,M) (C,N).sub.z and (Ti,M)N.sub.z (where M indicates a transition metal element of the group IVa, Va or VIa of the periodic table excepting Ti and z is within a range of about 0.7.ltoreq.z.ltoreq. about 0.85) and the atomic ratio of Ti contained in the binder to the transition metal element of the group IVa, Va or VIa of the periodic table excepting Ti is about 2/3 to 97/100 while the total tungsten concentration of tungsten contained in the form of at least one of tungsten carbide or the Ti compound described above in the binder is about 5 to 20 percent by weight.

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Hyogo, Japan

Mitsuhiro Goto