# US 10,870,154 B2 · Sintered body and cutting tool

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- Number: US 10,870,154 B2
- Document ID: US10870154B2
- Status: Granted
- Kind: B2
- Application number: 15/958,643
- Filed: 2018-04-20
- Published: 2018-08-23
- Granted: 2020-12-22
- Earliest claimed: 2015-02-26
- Assignees: Sumitomo Electric Industries, Ltd.
- Applicants: Sumitomo Electric Industries, Ltd.
- Inventors: Kentaro Chihara; Satoru Kukino
- Web page: https://patentgrep.com/patent/US10870154B2

## CPC

- B23B 27/14: Cutting tools of which the bits or tips {or cutting inserts} are of special material
- B23B 27/20: with diamond bits {or cutting inserts}
- C04B 35/583: based on boron nitride
- C22C 29/00: Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides {(C22C26/00 takes precedence)}
- C22C 29/12: based on oxides
- C22C 29/16: based on nitrides {(containing cubic BN or wurtzitic BN and diamond C22C26/00)}
- B23B: TURNING; BORING (arrangements for copying or controlling B23Q)
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE
- C22C: ALLOYS (treatment of alloys C21D, C22F)

## Abstract

A sintered body includes cubic boron nitride grains as hard phase grains, and has a thermal conductivity of less than 20 W·m−1·K−1, for cutting a nickel-based heat-resistant alloy formed of crystal grains having a coarse grain size represented by a grain size number of 5 or less defined by ASTM standard E112-13. A cutting tool includes this sintered body. Accordingly, the sintered body having high fracture resistance in addition to high wear resistance, as well as the cutting tool including the sintered body are provided.

## Claims

### Claim 1

A method for manufacturing a cut material, the method comprising:
preparing a nickel-based heat-resistant alloy formed of crystal grains having a coarse grain size represented by a grain size number of 5 or less defined by American Society for Testing and Materials standard E112-13; and
cutting the nickel-based heat-resistant alloy by using a sintered body comprising cubic boron nitride grains as hard phase grains and having a thermal conductivity of less than 15 W·m−1·K−1, wherein
the sintered body further comprises:
a binder;
different-type hard phase grains including at least one selected from the group consisting of silicon nitride, SiAlON, and alumina, as the hard phase grains other than the cubic boron nitride grains, and
a ratio VBN/VH of a volume VBN of the cubic boron nitride grains to a volume VH of the different-type hard phase grains is not less than 0.5 and not more than 1.5.

### Claim 2 (depends on 1)

The method for manufacturing the cut material according to claim 1, wherein
the SiAlON includes cubic SiAlON.

### Claim 3 (depends on 2)

The method for manufacturing the cut material according to claim 2, wherein
the SiAlON further includes at least one of α-SiAlON and β-SiAlON, and
a peak intensity ratio Rc of an intensity at an X-ray diffraction main peak of the cubic SiAlON to a sum of respective intensities at respective X-ray diffraction main peaks of the α-SiAlON, the β-SiAlON, and the cubic SiAlON is not less than 20%.

### Claim 4 (depends on 1)

The method for manufacturing the cut material according to claim 1, wherein
the binder includes at least one kind of binder selected from the group consisting of at least one kind of element out of titanium, zirconium, aluminum, nickel, and cobalt, nitrides, carbides, oxides, carbonitrides, and borides of the elements, and solid solutions thereof.

### Claim 5 (depends on 1)

The method for manufacturing the cut material according to claim 1, wherein
a content of the hard phase grains in the sintered body is not less than 60 vol % and not more than 90 vol %.

### Claim 6 (depends on 1)

The method for manufacturing the cut material according to claim 1, wherein
the sintered body has a Vickers hardness of not less than 20 GPa.

### Claim 7 (depends on 1)

The method for manufacturing the cut material according to claim 1, wherein
the nickel-based heat-resistant alloy includes nickel of not less than 50 mass % and not more than 55 mass %, chromium of not less than 17 mass % and not more than 21 mass %, niobium of not less than 4.75 mass % and not more than 5.50 mass %, molybdenum of not less than 2.80 mass % and not more than 3.30 mass %, and iron of not less than 12 mass % and not more than 24 mass %.

### Claim 8 (depends on 1)

The method for manufacturing the cut material according to claim 1, wherein
the cutting of the nickel-based heat-resistant alloy is performed by using a cutting tool comprising the sintered body.