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US4180400A
Expired / Lapsed
US
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Coated cemented carbide body and method of making such a body
Assignee: Santrade Ltd
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Filing: 1978-06-06
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Granted: 1979-12-25
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Expires: 1998-06-06
Abstract
Abstract An improved sintered cemented carbide body and method for making same is disclosed. The improved sintered cemented carbide body contains at least one metal carbide and a binder metal, on which body there is applied at least one thin, wear resistant surface layer consisting essentially of aluminum oxide and is characterized in that at least 85% of the aluminum oxide consists of the kappa form, the remainder, which mainly constitutes the alpha form, being formed as surface portions or spots having a size of at the most 10 mu m, the size and the occurrence of the surface portions being so adjusted that they lie within the area AOB in FIG. 1 of the attached drawing. The body is made by a method wherein a cemented carbide substrate is contacted with a gas containing an aluminum halide and a reducing agent at high temperature, characterized in that a dopant addition of tetravalent titanium, zirconium and/or hafnium ions is added to the gas in an amount of 0.03-0.5% of the totally supplied amount of gas.
Inventors
- 👤 Ulf K. H. Smith
- 👤 Jan N. Lindstrom
- 👤 Harold Mantle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:32
CPC Classifications
C; C23; C23C; C23C30/00; C23C30/005; B; B23; B23B; B23B27/00; B23B27/14; B23B27/148; C23C16/00; C23C16/22; C23C16/30; C23C16/40; C23C16/403; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12014
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
100 words
Sintered cemented carbide body containing at least one metal carbide and a binder metal, on which body there is applied at least one thin, wear resistant surface layer consisting essentially of aluminum oxide, characterized in that at least 85% of the aluminum oxide consists of the kappa form, the remainder if any, which mainly constitutes the alpha form, being formed as surface portions or spots having a size of at the most 10 μm, the size and the occurrence of the surface portions being so adjusted that they lie within the area AOB in FIG. 1 of the attached drawing.
Claim 2
Dependent Claim
100 words
Sintered cemented carbide body containing at least one metal carbide and a binder metal, on which body there is applied at least one thin, wear resistant surface layer consisting essentially of aluminum oxide, characterized in that at least 85% of the aluminum oxide consists of the kappa form, the remainder if any, which mainly constitutes the alpha form, being formed as surface portions or spots having a size of at the most 10 μm, the size and the occurrence of the surface portions being so adjusted that they lie within the area AOB in FIG. 1 of the attached drawing.
Claim 3
Dependent Claim
24 words
The sintered cemented carbide body of claim 1, wherein the alpha form of the aluminum oxide falls within the area A'OB' in FIG. 1.
Claim 4
Dependent Claim
23 words
Cemented carbide body according to claim 1, characterized in that the thickness of the aluminum oxide layer is from 0.1 to 20 μm.
Claim 5
Dependent Claim
21 words
The cemented carbide body of claim 1, wherein the aluminum oxide layer has a thickness of from 0.3 to 3 μm.
Claim 6
Dependent Claim
55 words
Cemented carbide body according to claim 1 or 3, characterized in that a thin intermediate layer of wear resistant carbide, nitride, carbonitride and/or boride, of one or more of the elements Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Si and/or B, is applied between the aluminum oxide layer and the cemented carbide body.
Claim 7
Dependent Claim
22 words
Cemented carbide body according to claim 5, characterized in that the thickness of the intermediate layer is from 1 to 8 μm.
Claim 8
Dependent Claim
22 words
Cemented carbide body according to claim 6, characterized in that the thickness of the intermediate layer is from 1.5 to 7 μm.
Claim 9
Dependent Claim
22 words
Cemented carbide body according to claim 6, characterized in that the intermediate layer consists of the carbide, nitride and/or carbonitride of titanium.
Claim 10
Dependent Claim
22 words
Cemented carbide body according to claim 1, characterized in that the aluminum oxide layer contains minor amounts of titanium, zirconium and/or hafnium.
Claim 11
Independent Claim
81 words
A method of making an aluminum-oxide coated cemented carbide body wherein a cemented carbide substrate is contacted with a gas containing an aluminum halide and a reducing agent at high temperature, characterized in that a dopant addition of tetravalent titanium, zirconium and/or hafnium ions is added to the gas in an amount of 0.03-0.5% of the totally supplied amount of gas whereby the cemented carbide substrate is coated with aluminum oxide, at least 85% of which is in the kappa form.
Claim 12
Independent Claim
81 words
A method of making an aluminum-oxide coated cemented carbide body wherein a cemented carbide substrate is contacted with a gas containing an aluminum halide and a reducing agent at high temperature, characterized in that a dopant addition of tetravalent titanium, zirconium and/or hafnium ions is added to the gas in an amount of 0.03-0.5% of the totally supplied amount of gas whereby the cemented carbide substrate is coated with aluminum oxide, at least 85% of which is in the kappa form.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-12-24 | 1983-06-25 | 1983-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-24 | 1987-06-25 | 1987-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-24 | 1991-06-25 | 1991-12-25 | $7700.00 | Window Closed / Lapsed |