US4093524A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bonding of refractory hard metal
Assignee: Kaiser Aluminum and Chemical Corp
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Filing: 1977-10-27
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Granted: 1978-06-06
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Expires: 1997-10-27
Abstract
Abstract The invention is directed to a method of bonding refractory hard metal materials such as TiB 2 wherein aluminum carbide is formed in situ at the interface between the refractory hard metal and a substrate. The bond formation is greatly accelerated by passing an electrical current across the interface.
Inventors
- 👤 John R. Payne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:47
CPC Classifications
C; C25; C25C; C25C7/00; C25C7/02; C25C7/025; C25C3/00; C25C3/06; C25C3/08
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
93 words
In an aluminum reduction cell comprising a shell defining a cavity with the inner surfaces thereof lined with refractory material, at least one electrode depending into the cavity, and a second electrode of opposite polarity to the first mentioned electrode wherein the surface of at least one of the electrodes is protected by refractory hard metal, the improvement comprising an aluminum carbide bond at the interface between the refractory hard metal and the protected electrode surface which is formed in situ at the interface thereof by reacting a carbonaceous material with molten aluminum.
Claim 2
Dependent Claim
93 words
In an aluminum reduction cell comprising a shell defining a cavity with the inner surfaces thereof lined with refractory material, at least one electrode depending into the cavity, and a second electrode of opposite polarity to the first mentioned electrode wherein the surface of at least one of the electrodes is protected by refractory hard metal, the improvement comprising an aluminum carbide bond at the interface between the refractory hard metal and the protected electrode surface which is formed in situ at the interface thereof by reacting a carbonaceous material with molten aluminum.
Claim 3
Dependent Claim
20 words
The improvement of claim 1 wherein the bond formation is accelerated by passing an electrical current across the said interface.
Claim 4
Dependent Claim
69 words
The aluminum reduction cell of claim 1 wherein the protected electrode surface is electrically connected to cathode bars disposed within the refractory lining on the floor of the shell and is inclined from the horizontal so that molten aluminum formed on the inclined cathodic surface during the operation of the cell will drain off except for a thin layer of molten aluminum which wets the refractory hard metal surface.
Claim 5
Dependent Claim
15 words
The improvement of claim 1 wherein the refractory hard metal consists essentially of titanium diboride.
Claim 6
Dependent Claim
51 words
A cathode structure for an aluminum reduction cell comprising a conductive cathode support and refractory hard metal shape bonded thereto by means of an aluminum carbide bond which is formed in situ at the interface thereof by reacting a carbonaceous material with molten aluminum under the influence of an electrical current.
Claim 7
Dependent Claim
51 words
A cathode structure for an aluminum reduction cell comprising a conductive cathode support and refractory hard metal shape bonded thereto by means of an aluminum carbide bond which is formed in situ at the interface thereof by reacting a carbonaceous material with molten aluminum under the influence of an electrical current.
Claim 8
Dependent Claim
46 words
A composite structure comprising a conductive support surface and planar shape of refractory hard metal bonded to the support surface by means of an aluminum carbide bond which is formed in situ at the interface thereof by reacting a finely divided carbonaceous material with molten aluminum.
Claim 9
Dependent Claim
46 words
A composite structure comprising a conductive support surface and planar shape of refractory hard metal bonded to the support surface by means of an aluminum carbide bond which is formed in situ at the interface thereof by reacting a finely divided carbonaceous material with molten aluminum.
Claim 10
Dependent Claim
21 words
The composite structure of claim 6 wherein the bond formation is accelerated by passing an electrical current across the said interface.
Claim 11
Independent Claim
46 words
A method of bonding a planar shape of refractory hard metal to a support surface comprising reacting a finely divided carbonaceous material with molten aluminum at the interface thereof to form aluminum carbide in situ which bonds the refractory hard metal plate to the support surface.
Claim 12
Independent Claim
46 words
A method of bonding a planar shape of refractory hard metal to a support surface comprising reacting a finely divided carbonaceous material with molten aluminum at the interface thereof to form aluminum carbide in situ which bonds the refractory hard metal plate to the support surface.
Claim 13
Dependent Claim
24 words
The method of claim 8 wherein the support surface is conductive and an electrical current is passed across the interface to accelerate bond formation.
Claim 14
Independent Claim
100 words
A method of forming an aluminum carbide bond between a protective RHM planar shape and a conductive cathodic surface in an aluminum reduction cell containing molten aluminum and a molten cryolite electrolyte comprising: A. providing finely divided carbonaceous material at the interface between the cathodic surface and the RHM shape; B. electrolyzing the reduction cell containing a molten cryolite electrolyte so as to pass an electric current across the said interface and thereby accelerate the reaction between molten aluminum at said interface with the finely divided carbonaceous material to form aluminum carbide which bonds the RHM to the cathodic surface.
Claim 15
Independent Claim
100 words
A method of forming an aluminum carbide bond between a protective RHM planar shape and a conductive cathodic surface in an aluminum reduction cell containing molten aluminum and a molten cryolite electrolyte comprising: A. providing finely divided carbonaceous material at the interface between the cathodic surface and the RHM shape; B. electrolyzing the reduction cell containing a molten cryolite electrolyte so as to pass an electric current across the said interface and thereby accelerate the reaction between molten aluminum at said interface with the finely divided carbonaceous material to form aluminum carbide which bonds the RHM to the cathodic surface.
Claim 16
Dependent Claim
38 words
The method of claim 10 wherein the carbonaceous material is graphitic in nature and is applied to the interface with a low molecular weight organic carrier to form a temporary bond between the RHM plate and cathodic surface.
Claim 17
Dependent Claim
32 words
The method of claim 10 wherein aluminum metal is provided at the interface along with the carbonaceous material during installation of the RHM shape on the cathodic surface of the reduction cell.
Claim 18
Dependent Claim
20 words
The method of claim 7 wherein the current density across the interface is about 2 to 20 amps/in 2 .
Claim 19
Dependent Claim
17 words
The method of claim 13 wherein the current density is about 4 to 10 amps/in 2 .
Claim 20
Dependent Claim
14 words
The method of claim 10 wherein the RHM plate consists essentially of titanium diboride.
Claim 21
Dependent Claim
16 words
The improvement of claim 4 wherein the titanium diboride contains less than 0.05% by weight oxygen.
Claim 22
Dependent Claim
16 words
The improvement of claim 4 wherein the titanium diboride contains less than 0.01% by weight oxygen.
Claim 23
Dependent Claim
16 words
The method of claim 15 wherein the titanium diboride contains less than 0.05% by weight oxygen.
Claim 24
Dependent Claim
16 words
The method of claim 15 wherein the titanium diboride contains less than 0.01% by weight oxygen.
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) | 1981-06-05 | 1981-12-05 | 1982-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-05 | 1985-12-05 | 1986-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-05 | 1989-12-05 | 1990-06-06 | $7700.00 | Window Closed / Lapsed |