High temperature oxidation resistant rare metal-free hard sintered body and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-2017304898-A1
Application number	US-201515517207-A
Country	US
Kind code	A1
Filing date	Oct 2, 2015
Priority date	Oct 10, 2014
Publication date	Oct 26, 2017
Grant date	—

Abstract

Provided is a hard sintered body which exhibits excellent high temperature oxidation resistance and has a high hardness at a high temperature. In the hard sintered body, a binder phase is contained at from 8.8 to 34.4 mol % and the balance is composed of a hard phase and inevitable impurities. The binder phase contains iron aluminide containing FeAl as a main component and alumina that is dispersed in iron aluminide and has a particle size of 1 μm or less. The hard phase is composed of at least one kind selected from carbides, nitrides, carbonitrides and borides of Group 4 metals, Group 5 metals and Group 6 metals in the periodic table, and solid solutions of these. This hard sintered body is obtained by mixing and pulverizing a binding particle powder containing an iron aluminide powder composed of at least one kind selected from FeAl 2 , Fe 2 Al 5 and FeAl 3 and a hard particle powder composed of at least one kind selected from carbides, nitrides, carbonitrides and borides of Group 4 metals, Group 5 metals and Group 6 metals in the periodic table and then sintering a mixed powder thus obtained.

First claim

1 . A hard sintered body comprising a binder phase at from 8.8 to 34.4 mol % and the balance being a hard phase and inevitable impurities, wherein
the binder phase contains iron aluminide containing FeAl as a main component and alumina that is dispersed in the iron aluminide and has a particle size of 1 μm or less, and the hard phase includes at least one kind selected from carbides, nitrides, carbonitrides and borides of Group 4 metals, Group 5 metals and Group 6 metals in the periodic table, and solid solutions of these.]

2 . The hard sintered body according to claim 1 , wherein the hard phase includes at least one kind selected from carbide, nitride, carbonitride and boride of Ti, and solid solutions of these.

3 . The hard sintered body according to claim 1 , wherein the hard phase includes at least either of tungsten carbide or a solid solution of tungsten carbide.

4 . The hard sintered body according to claim 1 , wherein the binder phase further contains at least one kind selected from boron, silicon, chromium, niobium and molybdenum.

5 . The hard sintered body according to claim 1 , wherein a content of the alumina in the binder phase is from 24.2 to 50.0 mol %.

6 . The hard sintered body according to claim 1 , wherein a content of aluminum in iron aluminide in the binder phase is from 24.6 to 57.7 mol %.

7 . A method of manufacturing a hard sintered body, the method comprising:
a mixing and pulverizing step of mixing and pulverizing a binding particle powder containing an iron aluminide powder including at least one kind selected from FeAl 2 , Fe 2 Al 5 and FeAl 3 and a hard particle powder including at least one kind selected from carbides, nitrides, carbonitrides and borides of Group 4 metals, Group 5 metals and Group 6 metals in the periodic table to obtain a mixed powder; and a sintering step of sintering the mixed powder.

8 . The method of manufacturing a hard sintered body according to claim 7 , wherein the hard particle powder includes at least one kind selected from carbide, nitride, carbonitride and boride of Ti.

9 . The method of manufacturing a hard sintered body according to claim 7 , wherein the hard particle powder includes tungsten carbide.

10 . The method of manufacturing a hard sintered body according to claim 7 , wherein
a content of the iron aluminide powder in the mixed powder is from 2.4 to 24.4 mol %, and a content of the hard particle powder in the mixed powder is from 75.6 to 97.6 mol %.

11 . The method of manufacturing a hard sintered body according to claim 7 , wherein the binding particle powder further contains at least one kind of additive powder selected from boron, silicon, chromium, niobium and molybdenum.

12 . The method of manufacturing a hard sintered body according to claim 7 , wherein the binding particle powder further contains an iron-based powder including at least one kind selected from Fe, FeB, Fe 3 Al and FeAl.

13 . The method of manufacturing a hard sintered body according to claim 7 , wherein the mixing and pulverizing step includes a stage of wet mixing and pulverizing the binding particle powder and the hard particle powder by using an organic solvent until the mixed powder containing a predetermined amount of oxygen is obtained to obtain the mixed powder.

14 . The method of manufacturing a hard sintered body according to claim 7 , wherein the mixing and pulverizing step includes a stage of dry mixing and pulverizing the binding particle powder and the hard particle powder in a mill vessel in a vacuum or a mill vessel purged with argon or nitrogen and then exposing a mixed powder of the binding particle powder and the hard particle powder to the atmospheric air until the mixed powder containing a predetermined amount of oxygen is obtained to obtain the mixed powder.

15 . The method of manufacturing a hard sintered body according to claim 13 , wherein the sintering step includes a stage of pressure molding the mixed powder and then sintering a pressure molded mixed powder in a vacuum atmosphere, an argon atmosphere or a nitrogen atmosphere.

16 . The method of manufacturing a hard sintered body according to claim 13 , wherein the sintering step includes a stage of sintering the mixed powder in a vacuum atmosphere, an argon atmosphere or a nitrogen atmosphere while pressurizing the mixed powder.

17 . A cutting or wear-resistant tool comprising the hard sintered body according to claim 1 as a raw material.

Assignees

• Nat Inst Advanced Ind Science & Tech

Inventors

• Shimojima Koji
• FURUSHIMA Ryouichi
• Hosokawa Hiroyuki
• Katou Kiyotaka
• Matsumoto Akihiro

Classifications

• B22F1/10

  Metallic powder containing lubricating or binding agents; Metallic powder containing organic material · CPC title

• B22F2005/001

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

• B22F2998/10

  Processes characterised by the sequence of their steps · CPC title

• B22F2201/11

  Argon · CPC title

• C22C29/16

  based on nitrides {(containing cubic BN or wurtzitic BN and diamond C22C26/00)} · CPC title