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US4911989A Expired / Lapsed US ⏱️ 0.0 years remaining

Surface-coated cemented carbide and a process for the production of the same

Assignee: Sumitomo Electric Industries Ltd
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Filing: 1989-04-10
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Granted: 1990-03-27
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Expires: 2009-04-10
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Abstract

Abstract A coated cemented carbide alloy having jointly a high toughness and high wear resistance is produced by specifying the cooling rate during sintering in efficient manner, which alloy comprises a cemented carbide substrate consisting of a hard phase of at least one member selected from the group consisting of carbides, nitrides and carbonitrides of Group IVa, Va and VIa metals of Periodic Table and a binder phase consisting of at least one member selected from the iron group metals, and a monolayer or multilayer, provided thereon, consisting of at least one member selected from the group consisting of carbides, nitrides, oxides and borides of Group IVa, Va and VIa metals of Periodic Table, solid solutions thereof and aluminum oxide, in which the hardness of the cemented carbide substrate in the range of 2 to 5 μm from the interface between the coating layer and substrate is 800 to 1300 kg/mm 2 by Vickers hardness at a load of 500 g, is monotonously increased toward the interior of the substrate and becomes constant in the range of about 50 to 100 μm from the interface.

Inventors

  • 👤 Nakano Minoru
  • 👤 Tobioka Masaaki
  • 👤 Nomura Toshio

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 09:28
CPC Classifications
C; C23; C23C; C23C28/00; C22; C22C; C22C29/00; C22C29/02; C22C29/04; C23C30/00; C23C30/005; C25; C25D; C25D13/00; C25D13/04; C25D13/06; B; B22; B22F; B22F2998/00; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/12021; Y10T428/12028; Y10T428/12049; Y10T428/12056; Y10T428/12458

Claims Analysis

Total Claims: 26
Claim 1
Independent Claim 161 words
A surface coated cemented carbide comprising a cemented carbide substrate consisting of a hard phase of at least one member selected from the group consisting of carbides, nitrides and carbonitrides of Group IVa, Va and VIa metals of Periodic Table and a binder phase consisting of at least one member selected from the iron group metals, and a monolayer or multilayer, provided thereon, consisting of at least one member selected from the group consisting of carbides, nitrides, oxides and borides of Group IVa, Va and VIa metals of Periodic Table, solid solutions thereof and aluminum oxide, in which the hardness of the cemented carbide substrate in the range of 2 to 5 μm from the interface between the coating layer and substrate is 700 to 1300 kg/mm 2 by Vickers hardness at a load of 500 g, is monotonously increased toward the interior of the substrate and becomes constant in the range of about 50 to 100 μm from the interface.
Claim 2
Dependent Claim 161 words
A surface coated cemented carbide comprising a cemented carbide substrate consisting of a hard phase of at least one member selected from the group consisting of carbides, nitrides and carbonitrides of Group IVa, Va and VIa metals of Periodic Table and a binder phase consisting of at least one member selected from the iron group metals, and a monolayer or multilayer, provided thereon, consisting of at least one member selected from the group consisting of carbides, nitrides, oxides and borides of Group IVa, Va and VIa metals of Periodic Table, solid solutions thereof and aluminum oxide, in which the hardness of the cemented carbide substrate in the range of 2 to 5 μm from the interface between the coating layer and substrate is 700 to 1300 kg/mm 2 by Vickers hardness at a load of 500 g, is monotonously increased toward the interior of the substrate and becomes constant in the range of about 50 to 100 μm from the interface.
Claim 3
Dependent Claim 36 words
The surface coated cemented carbide as claimed in claim 1, wherein the hardness of the cemented carbide substrate in the range of 2 to 5 μm from the interface is 950 to 1250 kg/mm 2 .
Claim 4
Dependent Claim 37 words
The surface coated cemented carbide as claimed in claim 1, wherein the hardness of the cemented carbide substrate in the range of about 50 to 100 μm from the interface is 1500 to 1700 kg/mm 2 .
Claim 5
Dependent Claim 40 words
The surface coated cemented carbide as claimed in claim 1, wherein the vicinity of the surface of the cemented carbide substrate consists of a layer consisting predominantly of WC and Co and having a thickness of 5 to 10 μm.
Claim 6
Dependent Claim 51 words
The surface coated cemented carbide as claimed in claim 1, wherein the quantity of the binder phase in the cemented carbide substrate, in the range of 2-20 μm to 50-100 μm from the interface is 1.5 to 7 times by weight as much as the average quantity of the binder phase.
Claim 7
Dependent Claim 53 words
The surface coated cemented carbide as claimed in claim 1, wherein the quantity of the binder phase in the cemented carbide substrate in the range of 2 to 20 μm from the interface is 1.5 to 7 times by weight as much as that in the range of about 50 to 100 μm.
Claim 8
Dependent Claim 58 words
The surface coated cemented carbide as claimed in claim 1, wherein when the binder phase consists of Co, the quantity of free carbon is 1 to 2.4% by weight based on that of Co, and when the binder phase consists of Ni, the quantity of free carbon is 0.5 to 2.2% by weight based on that of Ni.
Claim 9
Dependent Claim 39 words
The surface coated cemented carbide as claimed in claim 1, wherein the quantities of free carbon [FC] and nitrogen [N] in the cemented carbide substrate have the following relationship: 0.06≦[FC]+(12/14)×[N]≦0.17 wherein [FC] and [N] are represented by weight %.
Claim 10
Dependent Claim 39 words
The surface coated cemented carbide as claimed in claim 1, wherein the quantity of the binder phase in the range of up to 5 μm from the interface is less than in the interior of the cemented carbide substrate.
Claim 11
Dependent Claim 48 words
The surface coated cemented carbide as claimed in claim 1, wherein the content of the binder phase in the cemented carbide substrate in the range of up to 3 μm from the interface is less than that in the range of lower than 3 μm from the interface.
Claim 12
Dependent Claim 48 words
The surface coated cemented carbide as claimed in claim 1, wherein the cemented carbide substrate consists of 10 to 95% by weight of WC, 1 to 70% by weight of a mixed carbonitride of Ti, W and Ta, and/or Nb, and 3 to 20% by weight of Co.
Claim 13
Dependent Claim 29 words
The surface coated cemented carbide as claimed in claim 1, wherein Co or Co and C in the surface layer are removed by a chemical, mechanical or electrochemical treatment.
Claim 14
Dependent Claim 78 words
A process for the production of the surface coated cemented carbide as claimed in claim 1, which comprises mixing and sintering starting materials corresponding to the components for the hard phase and binder phase or being capable of in situ forming these components through decomposition or reaction, cooling the mixture at a cooling rate of 0.1° to 10° C./min and coating the resulting cemented carbide substrate with coating materials corresponding to the components for the monolayer or multilayer.
Claim 15
Dependent Claim 31 words
The process as claimed in claim 13, wherein the cooling is carried out at a cooling rate of 0.1° to 10° C./min within a temperature range of 1310° to 1225° C.
Claim 16
Dependent Claim 36 words
The process as claimed in claim 13, wherein the mixture to be cooled has contents of free carbon [FC] and nitrogen [N] satisfying the relationship of: 0.06≦[FC]+(12/14)×[N]≦0.17 wherein [FC] and [N] are represented by weight %.
Claim 17
Dependent Claim 23 words
The process as claimed in claim 13, wherein the sintering is carried out while suppressing the denitrification reaction until cooling to 1310° C.
Claim 18
Dependent Claim 35 words
The process as claimed in claim 16, wherein the denitrification reaction is suppressed by introducing at least one member selected from the group consisting of N 2 , CH 4 , H 2 and Ar.
Claim 19
Dependent Claim 25 words
The process as claimed in claim 14, wherein the cooling from 1310° to 1225° C. is carried out in vacuum or in an oxidizing atmosphere.
Claim 20
Dependent Claim 35 words
The process as claimed in claim 13, wherein the cemented carbide substrate before coating is subjected to a chemical, mechanical or electrochemical treatment to remove Co or Co and C from the surface layer thereof.
Claim 21
Dependent Claim 73 words
A process for the production of the surface coated cemented carbide as claimed in claim 1, which comprises mixing and sintering starting materials corresponding to the components for the hard phase and binder phase or being capable of in situ forming these components through decomposition or reaction, cooling the mixture in a period of time of from 10 minutes to 15 hours within a temperature range of from 1310° C. to 1225° C.
Claim 22
Dependent Claim 36 words
The process as claimed in claim 20, wherein the mixture to be cooled has contents of free carbon [FC] and nitrogen [N] satisfying the relationship of: 0.06≦[FC]+(12/14)×[N]≦0.17 wherein [FC] and [N] are represented by weight %.
Claim 23
Dependent Claim 23 words
The process as claimed in claim 20, wherein the sintering is carried out while suppressing the denitrification reaction until cooling to 1310° C.
Claim 24
Dependent Claim 35 words
The process as claimed in claim 22, wherein the denitrification reaction is suppressed by introducing at least one member selected from the group consisting of N 2 , CH 4 , H 2 and Ar.
Claim 25
Dependent Claim 20 words
The process as claimed in claim 14, wherein the cooling is carried out in vacuum or in an oxidizing atmosphere.
Claim 26
Dependent Claim 35 words
The process as claimed in claim 20, wherein the cemented carbide substrate before coating is subjected to a chemical, mechanical or electrochemical treatment to remove Co or Co and C from the surface layer thereof.

References Cited (Backward Citations)

US32111A Cited
US3999953A Cited
US3999954A Cited
USRE32111E Cited
US4610931A Cited
US4830930A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-03-26 1993-09-25 1994-03-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-03-26 1997-09-25 1998-03-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-03-26 2001-09-25 2002-03-27 $7700.00 Window Closed / Lapsed

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