# US 11,441,209 B2 · Cemented carbide and cutting tool including same

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- Number: US 11,441,209 B2
- Document ID: US11441209B2
- Status: Granted
- Kind: B2
- Application number: 17/599,570
- Filed: 2021-03-23
- Published: 2022-03-24
- Granted: 2022-09-13
- Earliest claimed: 2020-04-15
- Assignees: Sumitomo Electric Hardmetal Corp.
- Applicants: Sumitomo Electric Hardmetal Corp.
- Inventors: Kosuke Fukae; Yasuki Kido; Masami Watanabe; Shinya Imamura
- Web page: https://patentgrep.com/patent/US11441209B2

## CPC

- C22C 29/08: based on tungsten carbide
- B26D 1/0006: {Cutting members therefor}
- B22F 2005/001: {Cutting tools, earth boring or grinding tool other than table ware}
- B22F 2998/10: Processes characterised by the sequence of their steps
- B23B 2224/28: Titanium carbide
- B23B 2224/32: Titanium carbide nitride (TiCN)
- B26D 2001/002: {Materials or surface treatments therefor, e.g. composite materials}
- C22C: ALLOYS (treatment of alloys C21D, C22F)
- B26D: CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING (for growing crops or plants A01D, A01G; for fodder or straw A01F; for bulk butter A01J; for dough A21C; slaughtering A22B; for tobacco, cigars or cigarettes A24; marking-out, perforating or making buttonholes A41H25/00; manufacturing footwear A43D; brushmaking A46D; surgery A61B; disintegrating, mincing or shredding in general B02C; cutting wire, making pins or nails B21F, B21G; of the kind used formetal B23; cutting by abrasive fluid jets B24C5/02; hand-held cutting tools B26B; perforating, cutting-out, stamping-out or punching, or severing by means other than cutting B26F; for wood B27; for stone B28D; working of plastics or substances in a plastic state B29; making boxes, cartons, envelopes or bags, of paper or similarly worked materials, e.g. metal foil, B31B; article or web delivery apparatus incorporating cutting or line-perforating devices B65H35/00; for leather or upholstery B68, C14B; for glass C03B; making matches C06F; for peat C10F; for sugar C13B45/00; for textile materials D06H; civil engineering, building, mining, see Section E; for light guides G02B6/25; cutting processed photographic material G03D15/04)
- B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B23B: TURNING; BORING (arrangements for copying or controlling B23Q)

## Abstract

A cemented carbide includes first hard phase grains, second hard phase grains, third hard phase grains, and a metal binder phase, wherein the cemented carbide has a total of 70 unit regions, the number of unit regions each having a percentage of less than 0.43% or more than 2.43% is ≤10 among the total of 70 unit regions, the percentage being a percentage of the total number of the second and the third hard phase grains in each unit region with respect to the total number of the second and the third hard phase grains in the total of 70 unit regions, and in a total of 10 unit regions existing in a fourth row in a longitudinal direction, a percentage of the number of the third hard phase grains with respect to the total number of the second and the third hard phase grains is 5% to 15%.

## Claims

### Claim 1

A cemented carbide comprising first hard phase grains, second hard phase grains, third hard phase grains, and a metal binder phase, wherein
each of the first hard phase grains includes tungsten carbide,
each of the second hard phase grains has a core portion in a form of a grain and a peripheral portion that coats at least a portion of the core portion,
the core portion is composed of a first composite carbonitride represented by Ti1-X-ZNbXMZC1-YNY,
the peripheral portion is composed of a second composite carbonitride, the second composite carbonitride being a carbonitride that has a composition different from a composition of the core portion and that at least includes titanium, niobium, and tungsten,
the M represents at least one element selected from a group consisting of vanadium, chromium, and molybdenum,
the X is more than or equal to 0.1 and less than or equal to 0.2,
the Y is more than or equal to 0.3 and less than or equal to 0.6,
the Z is more than or equal to 0 and less than or equal to 0.02,
each of the third hard phase grains consisting of the first composite carbonitride,
the metal binder phase includes an iron group element,
the cemented carbide has a total of 70 unit regions,
the total of 70 unit regions are provided by continuously arranging 7 unit regions in a longitudinal direction and 10 unit regions in a lateral direction in an electron microscope image obtained by imaging an arbitrary cross section of the cemented carbide at a magnification of 1500×, each of the unit regions being constituted of a square having each side of 8 μm,
the number of unit regions each having a percentage of less than 0.43% or more than 2.43% is less than or equal to 10 among the total of 70 unit regions,
the percentage is a percentage of the total number of the number of the second hard phase grains and the number of the third hard phase grains in each unit region with respect to the total number of the number of the second hard phase grains and the number of the third hard phase grains in the total of 70 unit regions,
the number of the second hard phase grains in the unit region is the number of second hard phase grains having core portions each having a grain size of more than or equal to 0.2 μm and less than or equal to 3 μm in the unit region,
the number of the third hard phase grains in the unit region is the number of third hard phase grains each having a grain size of more than or equal to 0.5 μm and less than or equal to 2.5 μm in the unit region, and
in a total of 10 unit regions existing in a fourth row of the total of 70 unit regions in the longitudinal direction in the cemented carbide, a percentage of the number of the third hard phase grains each having a grain size of more than or equal to 0.5 μm and less than or equal to 2.5 μm with respect to the total number of the number of the second hard phase grains having the core portions each having a grain size of more than or equal to 0.2 μm and less than or equal to 3 μm and the number of the third hard phase grains each having a grain size of more than or equal to 0.5 μm and less than or equal to 2.5 μm is more than or equal to 5% and less than or equal to 15%.

### Claim 2 (depends on 1)

The cemented carbide according to claim 1, wherein an average thickness of the peripheral portions is more than or equal to 10 nm and less than or equal to 100 nm.

### Claim 3 (depends on 1)

The cemented carbide according to claim 1, wherein an average grain size of the core portions is more than or equal to 0.2 μm and less than or equal to 2 μm.

### Claim 4 (depends on 1)

The cemented carbide according to claim 1, wherein an average grain size of the third hard phase grains is more than or equal to 0.5 μm and less than or equal to 2.5 μm.

### Claim 5 (depends on 1)

The cemented carbide according to claim 1, wherein the cemented carbide includes more than or equal to 2 volume % and less than or equal to 10 volume % of the second hard phase grains.

### Claim 6 (depends on 1)

The cemented carbide according to claim 1, wherein the cemented carbide includes more than or equal to 3 volume % and less than or equal to 20 volume % of the third hard phase grains.

### Claim 7 (depends on 1)

A cutting tool comprising the cemented carbide recited in-claim 1.

### Claim 8 (depends on 7)

The cutting tool according to claim 7, comprising: a substrate composed of the cemented carbide; and a coating film that coats the substrate.