Cermet, and method for manufacturing same, as well as cutting tool

Patent metadata

Field	Value
Publication number	US-2016369380-A1
Application number	US-201414899097-A
Country	US
Kind code	A1
Filing date	Jun 19, 2014
Priority date	Jun 28, 2013
Publication date	Dec 22, 2016
Grant date	—

Abstract

A cermet ( 1 ) includes a bonding phase ( 2 ) and a hard phase ( 4 ). The hard phase ( 4 ) includes: a first hard phase ( 5 ) composed of TiCN; and a second hard phase ( 6 ) composed of a composite carbonitride of Ti, which is greater than the average particle diameter of the first hard phase ( 5 ). The cermet ( 1 ) further includes an aggregate part ( 10 ) formed by interlinking parts of the second hard phase ( 6 ). The second hard phase ( 6 ) forming the aggregate part ( 10 ) includes a 2 a -th hard phase ( 7 ) having a maximum W content of an inner part thereof that is more than 1.1 times as great as an average W content of an outer circumferential part thereof, in terms of mass ratio. The aggregate part ( 10 ) composes a proportion of from 20% to 60% of the cermet ( 1 ) in terms of surface area.

First claim

1 . A cermet comprising:
a bonding phase comprising at least one of Co and Ni as a main component; a hard phase composed of a carbonitride of at least one metal selected from among group IV, group V, and group VI metals of the periodic table; the hard phase comprising:
a first hard phase composed of TiCN having an average particle diameter of from 0.05 μm to 1 μm; and
a second hard phase having an average particle diameter of from 0.2 μm to 2 μm which is greater than the average particle diameter of the first hard phase, and composed of a composite carbonitride of Ti and at least one metal other than Ti selected from among group IV, group V, and group VI metals of the periodic table; and an aggregate part formed by interlinking parts of the second hard phase, the aggregate part having a particle diameter that is at least three times as great as the average particle diameter of the second hard phase; wherein the second hard phase comprises a 2a-th hard phase having a 2a-th maximum W content of an inner part thereof that is more than 1.1 times as great as an 2a-th average W content of an outer circumferential part thereof, the aggregate part composes a proportion of from 20% to 60% of the cermet, and a carbon content of the cermet is from 6.00% to 6.50% in terms of mass of the cermet.

2 . The cermet according to claim 1 , wherein
the second hard phase comprises a 2b-th hard phase having a 2b-th maximum W content of an inner part thereof that is equal to or less than 1.1 times as great as an 2b-th average W content of an outer circumferential part thereof.

3 . The cermet according to claim 1 , wherein
the hard phase further comprises a third hard phase formed of a core part that is composed of TiCN and an outer circumferential part thereof that is composed of a composite carbonitride of Ti and at least one metal other than Ti selected from among group IV, group V, and group VI metals of the periodic table.

4 . The cermet according to claim 1 , wherein
residual stress on the TiCN is from −500 MPa to −1200 MPa, residual stress on the composite carbonitride is from −1000 MPa to −1500 MPa, and residual stress on the bonding phase is from −400 MPa to −800 MPa.

5 . A method for manufacturing a cermet, comprising:
forming a compound powder by combining a TiCN powder, at least one of a carbide powder, a nitride powder, and a carbonitride powder, other than TiCN, of a metal selected from among group IV, group V and group VI metals of the periodic table, at least one of a Co powder and a Ni powder, and at least one of a metallic W powder and a WC1-x powder (where 0<x≦1); and baking the forming compound under conditions of:
(a) raising a temperature from room temperature to 1200° C.;
(b) in a vacuum, raising the temperature from 1200° C. to a baking temperature T1 of from 1330° C. to 1380° C. at a temperature increase rate of from 0.1° C./min to 2° C./min;
(c) in one of the vacuum and an inert gas atmosphere at from 30 Pa to 2000 Pa, raising the temperature from the baking temperature T1 to a baking temperature T2 of from 1500° C. to 1600° C. at a temperature increase rate of from 4° C./min to 15° C./min; and
(d) in one of the vacuum and the inert gas atmosphere at from 30 Pa to 2000 Pa, maintaining the baking temperature T2 for from 0.5 hours to 2 hours, and lowering the temperature.

6 . A cutting tool comprising the cermet described in claim 1 as a base.

Assignees

• Kyocera Corp

Inventors

• Kinoshita Hideyoshi

Classifications

• B22F2005/001

  Cutting tools, earth boring or grinding tool other than table ware · CPC title

• B22F2999/00

  Aspects linked to processes or compositions used in powder metallurgy · CPC title

• C22C29/04 Primary

  based on carbonitrides · CPC title

• C04B2235/6567

  Treatment time · CPC title

• B23B2222/16

  Cermet · CPC title