US5194138A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for creating a corrosion-resistant aluminum surface
Assignee: University of Southern California
•
Filing: 1990-07-20
•
Granted: 1993-03-16
•
Expires: 2010-07-20
Abstract
Abstract A method for treating the surface of an aluminum-based material so as to make the surface resistant to corrosion includes the steps of contacting the surface with an aqueous cerium non-halide solution and then contacting the surface with an aqueous cerium halide solution. These steps may optionally be followed by a step of positively charging the metal surface while in contact with an aqueous molybdenum solution.
Inventors
- 👤 Florian B. Mansfeld
- 👤 Hong Shih
- 👤 You Wang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:40
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/06; C23C22/48; C23C22/56
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
114 words
A method for treating the surface of an aluminum-based material so as to make the surface resistant to corrosion, comprising the steps of: (a) contacting the surface with an aqueous cerium non-halide solution for at least about 1 hour, the cerium non-halide solution having a pH of between about 4 and about 7 and being at a temperature of at least about 80° C.; and (b) contacting the metal surface from step (a) with an aqueous solution consisting essentially of a cerium halide for at least about 1 hour, the cerium halide solution having a pH of between about 4 and about 7 and being at a temperature of at least about 80° C.
Claim 2
Independent Claim
114 words
A method for treating the surface of an aluminum-based material so as to make the surface resistant to corrosion, comprising the steps of: (a) contacting the surface with an aqueous cerium non-halide solution for at least about 1 hour, the cerium non-halide solution having a pH of between about 4 and about 7 and being at a temperature of at least about 80° C.; and (b) contacting the metal surface from step (a) with an aqueous solution consisting essentially of a cerium halide for at least about 1 hour, the cerium halide solution having a pH of between about 4 and about 7 and being at a temperature of at least about 80° C.
Claim 3
Dependent Claim
14 words
The method of claim 1 wherein the aqueous cerium non-halide solution comprises nitrate ions.
Claim 4
Dependent Claim
16 words
The method of claim 1 wherein the aqueous cerium non-halide solution consists essentially of cerium nitrate.
Claim 5
Dependent Claim
22 words
The method of claim 1 wherein the surface is contacted with the aqueous cerium non-halide solution for at least about 1.5 hours.
Claim 6
Dependent Claim
22 words
The method of claim 1 wherein the surface is contacted with the aqueous cerium non-halide solution for at least about 2 hours.
Claim 7
Dependent Claim
20 words
The method of claim 1 wherein the pH of the cerium non-halide solution is between about 4.5 and about 5.5.
Claim 8
Dependent Claim
18 words
The method of claim 1 wherein the temperature of the cerium-non-halide solution is at least about 90° C.
Claim 9
Dependent Claim
19 words
The method of claim 1 wherein the temperature of the cerium non-halide solution is at least about 98° C.
Claim 10
Dependent Claim
15 words
The method of claim 1 wherein the cerium non-halide solution is at its boiling point.
Claim 11
Dependent Claim
14 words
The method of claim 1 wherein the aqueous cerium halide solution comprises chloride ions.
Claim 12
Dependent Claim
22 words
The method of claim 1 wherein the surface is contacted with the aqueous cerium halide solution for at least about 1.5 hours.
Claim 13
Dependent Claim
22 words
The method of claim 1 wherein the surface is contacted with the aqueous cerium halide solution for at least about 2 hours.
Claim 14
Dependent Claim
20 words
The method of claim 1 wherein the pH of the cerium halide solution is between about 4.5 and about 6.
Claim 15
Dependent Claim
19 words
The method of claim 1 wherein the temperature of the cerium -halide solution is at least about 90° C.
Claim 16
Dependent Claim
19 words
The method of claim 1 wherein the temperature of the cerium halide solution is at least about 98° C.
Claim 17
Dependent Claim
15 words
The method of claim 1 wherein the cerium halide solution is at its boiling point.
Claim 18
Dependent Claim
35 words
The method of claim 1 comprising the additional step of, after contacting the surface with the cerium non-halide and cerium halide solutions, positively charging the surface while contacting the surface with an aqueous molybdenum solution.
Claim 19
Dependent Claim
13 words
The method of claim 17 wherein the aqueous molybdenum solution contains molybdate ions.
Claim 20
Dependent Claim
21 words
The method of claim 17 wherein the surface is charged to a potential within the passive region of the aluminum-based material.
Claim 21
Dependent Claim
26 words
The method of claim 19 wherein the charge on the surface is between about 300 and about 800 mV above the corrosion potential of the material.
Claim 22
Dependent Claim
25 words
The method of claim 19 wherein the surface is charged between about 400 mV and about 600 mV above the corrosion potential of the material.
Claim 23
Independent Claim
131 words
A method for treating a surface of an aluminum-based material so as to make the surface resistant to corrosion, comprising the steps of: (a) contacting the surface with an aqueous cerium non-halide solution for at least about 1 hours, the cerium non-halide solution having a pH of between about 4 and about 7 and being at a temperature of at least about 80° C.; (b) contacting the surface from step (a) with an aqueous solution consisting essentially of a cerium halide for at least about 1 hour, the cerium halide solution having a pH of between about 4 and about 7 and being at a temperature of at least about 80° C.; and (c) positively charging the metal surface from step (b) while contacting the surface with an aqueous molybdenum solution.
Claim 24
Independent Claim
131 words
A method for treating a surface of an aluminum-based material so as to make the surface resistant to corrosion, comprising the steps of: (a) contacting the surface with an aqueous cerium non-halide solution for at least about 1 hours, the cerium non-halide solution having a pH of between about 4 and about 7 and being at a temperature of at least about 80° C.; (b) contacting the surface from step (a) with an aqueous solution consisting essentially of a cerium halide for at least about 1 hour, the cerium halide solution having a pH of between about 4 and about 7 and being at a temperature of at least about 80° C.; and (c) positively charging the metal surface from step (b) while contacting the surface with an aqueous molybdenum solution.
Claim 25
Dependent Claim
14 words
The method of claim 27 wherein the aqueous cerium non-halide solution comprises cerium nitrate.
Claim 26
Dependent Claim
22 words
The method of claim 27 wherein the surface is contacted with the aqueous cerium non-halide solution for at least about 1.5 hours.
Claim 27
Dependent Claim
22 words
The method of claim 22 wherein the surface is contacted with the aqueous cerium non-halide solution for at least about 2 hours.
Claim 28
Dependent Claim
20 words
The method of claim 22 wherein the pH of the cerium non-halide solution is between about 4.5 and about 5.5.
Claim 29
Dependent Claim
19 words
The method of claim 22 wherein the temperature of the cerium non-halide solution is at least about 90° C.
Claim 30
Dependent Claim
19 words
The method of claim 22 wherein the temperature of the cerium on-halide solution is at least about 98° C.
Claim 31
Dependent Claim
15 words
The method of claim 22 wherein the cerium non-halide solution is at its boiling point.
Claim 32
Dependent Claim
14 words
The method of claim 22 wherein the aqueous cerium halide solution comprises cerium chloride.
Claim 33
Dependent Claim
22 words
The method of claim 22 wherein the surface is contacted with the aqueous cerium halide solution for at least about 1.5 hours.
Claim 34
Dependent Claim
22 words
The method of claim 22 wherein the surface is contacted with the aqueous cerium halide solution for at least about 2 hours.
Claim 35
Dependent Claim
20 words
The method of claim 22 wherein the pH of the cerium halide solution is between about 4.5 and about 6.
Claim 36
Dependent Claim
19 words
The method of claim 22 wherein the temperature of the cerium halide solution is at least about 90° C.
Claim 37
Dependent Claim
19 words
The method of claim 22 wherein the temperature of the cerium halide solution is at least about 98° C.
Claim 38
Dependent Claim
15 words
The method of claim 22 wherein the cerium halide solution is at its boiling point.
Claim 39
Dependent Claim
21 words
The method of claim 22 wherein the surface is charged to a potential within the passive region of the aluminum-based material.
Claim 40
Dependent Claim
19 words
The method of claim 22 wherein the charge on the surface is between about 300 and about 800 mV.
Claim 41
Dependent Claim
18 words
The method of claim 22 wherein the surface is charged between about 400 mV and about 600 mV.
Claim 42
Independent Claim
14 words
The method of claims 1 or 22 wherein the surface consists essentially of aluminum.
Claim 43
Independent Claim
16 words
The method of claims 13 or 22 wherein the surface comprises an aluminum metal matrix composite.
Claim 44
Independent Claim
39 words
The method of claims 1 or 35 comprising the further steps of, prior to performing step (a), removing metal oxides from the surface and then reoxidizing the metal surface to create a uniform aluminum oxide layer on the surface.
References Cited (Backward Citations)
US2512493A
Cited
US3960676A
Cited
US3969152A
Cited
US4610732A
Cited
WO1988006639A1
Cited
US4992115A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-03-15 | 1996-09-14 | 1997-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-03-15 | 2000-09-14 | 2001-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-03-15 | 2004-09-14 | 2005-03-16 | $7700.00 | Window Closed / Lapsed |