Surface-coated cutting tool and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-2019232385-A1
Application number	US-201716328210-A
Country	US
Kind code	A1
Filing date	May 25, 2017
Priority date	Aug 25, 2016
Publication date	Aug 1, 2019
Grant date	—

Abstract

A surface-coated cutting tool includes a base material and a coating formed on the base material. The base material is a cemented carbide or a cermet. A surface of the base material includes a rake face, a flank face, and a cutting edge face connecting the rake face to the flank face. The base material has an oxygen concentration of less than or equal to 1 at. % at a depth position of 0.4 μm from the cutting edge face. The coating includes a hard layer. A topmost layer in the hard layer has a compressive stress of more than or equal to 1.5 GPa in absolute value.

First claim

1 . A surface-coated cutting tool comprising a base material and a coating formed on the base material,
the base material being a cemented carbide or a cermet, a surface of the base material including a rake face, a flank face, and a cutting edge face connecting the rake face to the flank face, the base material having an oxygen concentration of less than or equal to 1 at. % at a depth position of 0.4 μm from the cutting edge face, the coating including a hard layer, a topmost layer in the hard layer having a compressive stress of more than or equal to 1.5 GPa in absolute value.

2 . The surface-coated cutting tool according to claim 1 , wherein the base material has an oxygen concentration of less than or equal to 10 at. % at a depth position of 0.2 μm from the cutting edge face.

3 . The surface-coated cutting tool according to claim 1 , wherein the topmost layer has a compressive stress of more than or equal to 3.5 GPa in absolute value.

4 . The surface-coated cutting tool according to claim 1 , wherein the hard layer is a compound layer made from:
at least one kind of first element selected from the group consisting of Group IV elements, Group V elements, and Group VI elements in the periodic table, Al, and Si; and at least one kind of second element selected from the group consisting of B, C, N, and O.

5 . The surface-coated cutting tool according to claim 1 , wherein the topmost layer is a layer made from an oxide containing Al.

6 . The surface-coated cutting tool according to claim 1 , wherein the cutting edge face of the base material has a strain of less than or equal to 0.07.

7 . A method for manufacturing a surface-coated cutting tool according to claim 1 , the method comprising:
preparing a base material precursor; producing a base material by machining a surface of the base material precursor; forming, on the base material, a coating including a hard layer; and imparting a compressive stress to the coating, the machining being one of
a first grinding process of alternately repeating wet grinding and dry grinding of the surface of the base material precursor;
a second grinding process of performing low-feed low-depth-of-cut wet grinding, or
a third grinding process of performing dry grinding.

Assignees

• Sumitomo Electric Hardmetal Corp

Inventors

• Imamura Shinya
• Kanaoka Hideaki
• Paseuth Anongsack
• Ono Satoshi
• Yoshimura Kouhei

Classifications

• C23C28/44

  characterized by a measurable physical property of the alternating layer or system, e.g. thickness, density, hardness · CPC title

• B23B27/148 Primary

  Composition of the cutting inserts · CPC title

• B23B27/145 Primary

  characterised by having a special shape · CPC title

• B23C5/20

  with removable cutter bits or teeth {or cutting inserts} · CPC title

• C23C2/12

  Aluminium or alloys based thereon · CPC title