Cemented carbide and cutting tool including same as substrate

Patent metadata

Field	Value
Publication number	US-2022016715-A1
Application number	US-202017294438-A
Country	US
Kind code	A1
Filing date	Jul 3, 2020
Priority date	Oct 25, 2019
Publication date	Jan 20, 2022
Grant date	—

Abstract

A cemented carbide includes a first hard phase, a second hard phase, and a binder phase, wherein the first hard phase is composed of tungsten carbide grains, the second hard phase is composed of carbide grains including niobium or tantalum as a constituent element, the binder phase includes cobalt, nickel, and chromium as constituent elements, at least part of the carbide grains further include tungsten as a constituent element, and when a volume ratio of the second hard phase to the cemented carbide is represented by A volume % and a volume ratio of a total of a niobium element and a tantalum element to the cemented carbide is represented by B volume %, a ratio A/B of A to B is more than 1.2.

First claim

1 . A cemented carbide comprising a first hard phase, a second hard phase, and a binder phase, wherein
the first hard phase is composed of tungsten carbide grains, the second hard phase is composed of carbide grains including niobium or tantalum as a constituent element, the binder phase includes cobalt, nickel, and chromium as constituent elements, at least part of the carbide grains further include tungsten as a constituent element, and a ratio A/B of A volume % representing a volume ratio of the second hard phase to the cemented carbide to B volume % representing a volume ratio of a total of a niobium element and a tantalum element to the cemented carbide is more than 1.2.

2 . The cemented carbide according to claim 1 , wherein a mass ratio of a total of a cobalt element, a nickel element, and a chromium element to the cemented carbide is more than or equal to 1 mass % and less than or equal to 20 mass %.

3 . The cemented carbide according to claim 1 , wherein an area ratio of the second hard phase to an arbitrary surface or arbitrary cross section of the cemented carbide is more than or equal to 1% and less than or equal to 30%.

4 . The cemented carbide according to claim 1 , wherein an average grain size of the tungsten carbide grains is more than or equal to 0.1 μm and less than or equal to 10 μm.

5 . The cemented carbide according to claim 1 , wherein an average grain size of the carbide grains is more than or equal to 0.1 μm and less than or equal to 5 μm.

6 . A cutting tool comprising the cemented carbide recited in claim 1 as a substrate.

7 . The cutting tool according to claim 6 , further comprising a coating film provided on the substrate.

Assignees

• Sumitomo Electric Industries

Inventors

• Yamanishi Takato
• Tsuda Keiichi

Classifications

• B23B27/14 Primary

  Cutting tools of which the bits or tips {or cutting inserts} are of special material · CPC title

• B22F3/1007

  Atmosphere (B22F3/1021 takes precedence) · CPC title

• C22C29/08 Primary

  based on tungsten carbide · CPC title

• B22F2998/10

  Processes characterised by the sequence of their steps · CPC title

• B23C5/16

  characterised by physical features other than shape · CPC title