US4649084A
Expired / Lapsed
US
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Process for adhering an oxide coating on a cobalt-enriched zone, and articles made from said process
Assignee: Carboloy Inc
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Filing: 1985-05-06
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Granted: 1987-03-10
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Expires: 2005-05-06
Abstract
Abstract An improved fabrication process for cobalt-enriched cemented carbide substrates is disclosed, in which an article is generally comprised of tungsten carbide, cobalt, and carbides, nitrides or carbonitrides of titanium, tantalum, and niobium, or mixtures thereof. In one aspect of the invention the article is contacted with nitrogen gas and then sintered in the absence of nitrogen gas to form a cobalt-enriched, B-1 phase-depleted zone. The article is then sintered in nitrogen gas to form a B-1 phase enriched layer on the surface of the article. Additionally, a metal oxide wear layer can be provided on the article.
Inventors
- 👤 Thomas E. Hale
- 👤 Warren C. Yohe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:23
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; B; B23; B23B; B23B27/00; B23B27/14; B23B27/148; C04B41/45; C04B41/52; C04B41/80; C04B41/81; C04B41/89; C22; C22C; C22C29/00; C22C29/02; C22C29/06; C22C29/08; C23; C23C; C23C16/00; C23C16/02; C23C16/0209; C23C16/22; C23C16/30; C23C16/40; C23C16/403; C23C30/00; C23C30/005; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/12028; Y10T428/12049; Y10T428/12056; Y10T428/12146; Y10T428/12493; Y10T428/12736; Y10T428/1275
Claims Analysis
Total Claims: 46
Claim 1
Independent Claim
112 words
A method of improving the adherence of an oxide coating on a tungsten carbide-based substrate, the composition of which comprises tungsten carbide, cobalt and at least one carbide, nitride or carbonitride of titanium, and at least one carbide, nitride or carbonitride of tantalum, niobium or mixtures thereof, comprising the steps of: (a) sintering the substrate in nitrogen gas at a temperature at or above the melting point of the cobalt phase for a period of time sufficient to cause the formation of a B-1 phase enriched layer on the surface of the sintered substrate; (b) oxidizing the surface of the substrate; and (c) depositing an oxide wear layer on the oxidized surface.
Claim 2
Independent Claim
112 words
A method of improving the adherence of an oxide coating on a tungsten carbide-based substrate, the composition of which comprises tungsten carbide, cobalt and at least one carbide, nitride or carbonitride of titanium, and at least one carbide, nitride or carbonitride of tantalum, niobium or mixtures thereof, comprising the steps of: (a) sintering the substrate in nitrogen gas at a temperature at or above the melting point of the cobalt phase for a period of time sufficient to cause the formation of a B-1 phase enriched layer on the surface of the sintered substrate; (b) oxidizing the surface of the substrate; and (c) depositing an oxide wear layer on the oxidized surface.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein the composition is a powder, and the powder is mechanically compacted prior to sintering the substrate in nitrogen gas.
Claim 4
Dependent Claim
51 words
The method of claim 2 wherein the compacted composition contains processing materials which promote compaction and further comprising heating the compacted composition in an atmosphere comprising hydrogen gas, a noble gas or mixtures thereof for a sufficient time to remove processing materials therefrom prior to sintering the substrate in nitrogen gas.
Claim 5
Dependent Claim
42 words
The method of claim 2 wherein the compacted composition contains processing materials which promote compaction and further comprising heating the compacted composition in a vacuum for a sufficient time to remove processing materials therefrom prior to sintering the substrate in nitrogen gas.
Claim 6
Dependent Claim
42 words
The method of claim 4 further comprising heating the compacted composition in a vacuum at a temperature of about 1000° C. to about 1300° C. for a sufficient time to remove contaminating gases therefrom prior to sintering the substrate in nitrogen gas.
Claim 7
Dependent Claim
40 words
The method of claim 4 further comprising heating the compacted composition in an atmosphere comprising hydrogen gas, a noble gas or mixtures thereof for a sufficient time to remove contaminating gases therefrom, prior to sintering the substrate in nitrogen gas.
Claim 8
Dependent Claim
27 words
The method of claim 1 wherein the substrate comprises about 70% to about 90% by weight tungsten carbide and about 5% to about 15% by weight cobalt.
Claim 9
Dependent Claim
32 words
The method of claim 1 wherein the substrate is sintered in nitrogen gas at a temperature of about 1300° C. to about 1500° C. for about 45 minutes to about 100 minutes.
Claim 10
Dependent Claim
22 words
The method of claim 8 wherein the pressure of the nitrogen gas is about 1 mm Hg to about 1,520 mm Hg.
Claim 11
Dependent Claim
45 words
The method of claim 1 wherein the surface of the substrate is oxidized by heating the surface at a temperature of about 800° C. to about 1400° C. for about 5 minutes to about 40 minutes in the presence of hydrogen gas containing carbon dioxide.
Claim 12
Dependent Claim
13 words
The method of claim 1 wherein the oxide wear layer is aluminum oxide.
Claim 13
Independent Claim
187 words
A method of preparing a cemented tungsten carbide cutting insert the composition of which comprises tungsten carbide, cobalt, and at least one carbide, nitride or carbonitride of titanium, and at least one carbide, nitride or carbonitride of tantalum, niobium or mixtures thereof, comprising the steps of: (a) contacting the composition in a pressed powder compacted state in the shape of a cutting insert at a temperature below the melting point of the cobalt phase with nitrogen gas for a time period sufficient to diffuse nitrogen gas into the insert; (b) increasing the temperature of the insert to at least the melting point of the cobalt phase; (c) sintering the insert at a temperture of at least the melting point of the cobalt phase in the absence of nitrogen gas for a period of time sufficient to form a cobalt-enriched, B-1 phase depleted zone; and (d) sintering the insert in nitrogen gas at a temperature at or above the melting point of the cobalt phase for a period of time sufficient to cause the formation of a B-1 phase enriched layer on the surface of the sintered insert.
Claim 14
Independent Claim
187 words
A method of preparing a cemented tungsten carbide cutting insert the composition of which comprises tungsten carbide, cobalt, and at least one carbide, nitride or carbonitride of titanium, and at least one carbide, nitride or carbonitride of tantalum, niobium or mixtures thereof, comprising the steps of: (a) contacting the composition in a pressed powder compacted state in the shape of a cutting insert at a temperature below the melting point of the cobalt phase with nitrogen gas for a time period sufficient to diffuse nitrogen gas into the insert; (b) increasing the temperature of the insert to at least the melting point of the cobalt phase; (c) sintering the insert at a temperture of at least the melting point of the cobalt phase in the absence of nitrogen gas for a period of time sufficient to form a cobalt-enriched, B-1 phase depleted zone; and (d) sintering the insert in nitrogen gas at a temperature at or above the melting point of the cobalt phase for a period of time sufficient to cause the formation of a B-1 phase enriched layer on the surface of the sintered insert.
Claim 15
Dependent Claim
25 words
The method of claim 12 further comprising: (e) oxidizing the surface of the insert; and (f) depositing an oxide wear layer on the oxidized surface.
Claim 16
Dependent Claim
38 words
The method of claim 13, wherein the insert in the pressed powder state contains processing materials which promote compaction, and further comprising heating the compacted composition in a vacuum for a sufficient time to remove processing materials therefrom.
Claim 17
Dependent Claim
47 words
The method of claim 13, wherein the insert in the pressed powder state contains processing materials which promote compaction, and further comprising heating the compacted composition in an atmosphere comprising hydrogen gas, a noble gas or mixtures thereof for a sufficient time to remove processing materials therefrom.
Claim 18
Dependent Claim
26 words
The method of claim 12 wherein the insert comprises at least about 2% by weight titanium carbide and at least about 1% by weight tantalum carbide.
Claim 19
Dependent Claim
26 words
The method of claim 12 wherein the insert comprises at least about 2% by weight titanium carbide and at least about 1% by weight niobium carbide.
Claim 20
Dependent Claim
24 words
The method of claim 12 wherein the insert is sintered in step (c) in the absence of nitrogen and in the presence of argon.
Claim 21
Dependent Claim
31 words
The method of claim 12 wherein the insert is sintered in nitrogen gas in step (d) at a pressure of at least about 1 mm Hg to about 1520 mm Hg.
Claim 22
Dependent Claim
27 words
The method of claim 12 wherein the composition comprises about 70% to about 90% by weight tungsten carbide and about 5% to about 15% by weight cobalt.
Claim 23
Dependent Claim
20 words
The method of claim 12 wherein the temperature in step (a) is from about 1100° C. to about 1280° C.
Claim 24
Dependent Claim
26 words
The method of claim 12 wherein the pressure of the nitrogen gas in step (a) is from about 1 mm Hg to about 1520 mm Hg.
Claim 25
Dependent Claim
25 words
The method of claim 12 wherein the pressure of nitrogen gas in step (a) is from about 400 mm Hg to about 800 mm Hg.
Claim 26
Dependent Claim
22 words
The method of claim 18 wherein the pressure of the argon gas is about 1 mm Hg to about 10 mm Hg.
Claim 27
Dependent Claim
29 words
The method of claim 12 wherein the insert is sintered in step (c) for about 45 minutes to about 100 minutes to form the cobalt-enriched, B-1 phase depleted zone.
Claim 28
Dependent Claim
28 words
The method of claim 12 wherein the insert is sintered in step (c) for about 70 minutes to about 90 minutes to form the cobalt-enriched, B-1 phase-depleted zone.
Claim 29
Dependent Claim
24 words
The method of claim 12 wherein the insert is sintered in step (c) at a temperature from about 1300° C. to about 1470° C.
Claim 30
Dependent Claim
24 words
The method of claim 12 wherein the insert is sintered in step (c) at a temperature from about 1430° C. to about 1470° C.
Claim 31
Dependent Claim
27 words
The method of claim 12 wherein the insert is sintered in nitrogen gas in step (d) at a temperature of about 1300° C. to about 1500° C.
Claim 32
Dependent Claim
27 words
The method of claim 12 wherein the insert is sintered in nitrogen gas in step (d) at a temperature of about 1400° C. to about 1440° C.
Claim 33
Dependent Claim
31 words
The method of claim 12 wherein the insert is sintered in nitrogen gas in step (d) at a nitrogen gas pressure of about 500 mm Hg to about 700 mm Hg.
Claim 34
Dependent Claim
20 words
The method of claim 31 comprising sintering the insert in nitrogen gas for about 5 minutes to about 100 minutes.
Claim 35
Dependent Claim
16 words
The method of claim 31 comprising sintering the insert in nitrogen gas for about 20 minutes.
Claim 36
Dependent Claim
43 words
The method of claim 13 wherein the surface of the insert is oxidized by heating the surface for about 5 minutes to about 40 minutes at a temperature of about 800° C. to about 1400° C. in a hydrogen atmosphere containing carbon dioxide.
Claim 37
Dependent Claim
20 words
The method of claim 34 wherein the concentration of carbon dioxide in the hydrogen atmosphere is about 20% by volume.
Claim 38
Dependent Claim
16 words
The method of claim 13 wherein the oxide wear layer is Al 2 O 3 .
Claim 39
Dependent Claim
60 words
An article comprising: (a) a tungsten carbide-based substrate containing cobalt and at least one carbide, nitride or carbonitride of titanium, and at least one carbide, nitride or carbonitride of tantalum, niobium or mixtures thereof; (b) a B-1 phase-depleted, cobalt-enriched zone substantially covering the substrate; and (c) a B-1 phase enriched zone on the surface of the B-1 phase-depleted, cobalt-enriched zone.
Claim 40
Dependent Claim
60 words
An article comprising: (a) a tungsten carbide-based substrate containing cobalt and at least one carbide, nitride or carbonitride of titanium, and at least one carbide, nitride or carbonitride of tantalum, niobium or mixtures thereof; (b) a B-1 phase-depleted, cobalt-enriched zone substantially covering the substrate; and (c) a B-1 phase enriched zone on the surface of the B-1 phase-depleted, cobalt-enriched zone.
Claim 41
Dependent Claim
37 words
The article of claim 37 further comprising: (d) a layer of oxidized B-1 phase on the surface of the B-1 phase enriched zone; and (e) an oxide wear layer substantially covering the layer of oxidized B-1 phase.
Claim 42
Dependent Claim
23 words
The article of claim 37 comprising at least about 2% by weight titanium carbide and at least about 1% by weight tantalum carbide.
Claim 43
Dependent Claim
23 words
The article of claim 37 comprising at least about 2% by weight titanium carbide and at least about 1% by weight niobium carbide.
Claim 44
Dependent Claim
18 words
The article of claim 37 wherein the substrate comprises about 70% to about 90% by weight tungsten carbide.
Claim 45
Dependent Claim
17 words
The article of claim 37 wherein the substrate comprises about 5% to about 15% by weight cobalt.
Claim 46
Dependent Claim
16 words
The article of claim 38 wherein the oxide wear layer is Al 2 O 3 .
References Cited (Backward Citations)
US32111A
Cited
US3736107A
Cited
US3971656A
Cited
US4063938A
Cited
US4049876A
Cited
US4018631A
Cited
US4150195A
Cited
US4276096A
Cited
US4239536A
Cited
US4277283A
Cited
US4300952A
Cited
US4320203A
Cited
GB2061324A
Cited
DE3039775A1
Cited
US4350528A
Cited
US4374685A
Cited
US4357382A
Cited
USRE32111E
Cited
GB2095702A
Cited
US4501786A
Cited
US4497874A
Cited
JPS6036635A
Cited
US4548786A
Cited
US4556607A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-09 | 1990-09-08 | 1991-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-09 | 1994-09-08 | 1995-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-09 | 1998-09-08 | 1999-03-10 | $7700.00 | Window Closed / Lapsed |