US3989876A
Expired / Lapsed
US
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Method of anodizing titanium to promote adhesion
Assignee: Boeing Co
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Filing: 1975-05-27
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Granted: 1976-11-02
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Expires: 1995-05-27
Abstract
Abstract Porous, adhesion-promoting oxide coatings are formed on titanium by anodizing in an aqueous solution containing fluoride ion and one or more oxidizing electrolytes at current densities of from 0.25 to 5 amp./ft. 2 .
Inventors
- 👤 Yukimori Moji
- 👤 J. Arthur Marceau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 03:37
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/02; C25D11/26
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
109 words
An adhesively bonded composite article comprising first and second adherends, said first adherend including a titanium element having an oxide layer on the surface thereof; and an adhesive system bonded to said oxide layer and to said second adherend, said oxide layer having been produced by anodizing said surface of said titanium element in an aqueous solution comprising fluoride ions and an oxidizing electrolyte, the pH of said solution being less than 6, the anodizing potential being from about 5 to about 40 volts, and the fluoride ion concentration being such as to result in a current density of from about 0.25 to about 5 amperes per square foot.
Claim 2
Dependent Claim
109 words
An adhesively bonded composite article comprising first and second adherends, said first adherend including a titanium element having an oxide layer on the surface thereof; and an adhesive system bonded to said oxide layer and to said second adherend, said oxide layer having been produced by anodizing said surface of said titanium element in an aqueous solution comprising fluoride ions and an oxidizing electrolyte, the pH of said solution being less than 6, the anodizing potential being from about 5 to about 40 volts, and the fluoride ion concentration being such as to result in a current density of from about 0.25 to about 5 amperes per square foot.
Claim 3
Dependent Claim
20 words
A composite of claim 1 wherein said current density is from about 0.5 to about 4 amperes per square foot.
Claim 4
Dependent Claim
18 words
A composite of claim 1 wherein the anodizing potential employed is from about 7.5 to about 20 volts.
Claim 5
Dependent Claim
20 words
A composite of claim 3 wherein said current density is from about 1 to about 3 amperes per square foot.
Claim 6
Dependent Claim
18 words
A composite of claim 1 wherein the anodizing potential employed is from about 10 to about 15 volts.
Claim 7
Dependent Claim
20 words
A composite of claim 5 wherein said current density is from about 1 to about 3 amperes per square foot.
Claim 8
Dependent Claim
24 words
The article of claim 1 wherein said oxidizing electrolyte comprises ions selected from the group consisting of dichromate, sulfate, phosphate, nitrate and mixtures thereof.
Claim 9
Dependent Claim
31 words
The article of claim 7 wherein the source of fluoride ion is selected from the group consisting of hydrogen fluoride, sodium fluoride, potassium fluoride, ammonium fluoride, ammonium bifluoride and mixtures thereof.
Claim 10
Dependent Claim
12 words
The article of claim 1 wherein said oxidizing electrolyte comprises dichromate ions.
Claim 11
Dependent Claim
31 words
The article of claim 9 wherein the source of fluoride ion is selected from the group consisting of hydrogen fluoride, sodium fluoride, potassium fluoride, ammonium fluoride, ammonium bifluoride and mixtures thereof.
Claim 12
Dependent Claim
31 words
The article of claim 1 wherein the source of fluoride ion is selected from the group consisting of hydrogen fluoride, sodium fluoride, potassium fluoride, ammonium fluoride, ammonium bifluoride and mixtures thereof.
Claim 13
Dependent Claim
20 words
The article of claim 1 wherein the temperature of said solution is from about 50° F. to about 80° F.
Claim 14
Dependent Claim
24 words
The article of claim 6 wherein said oxidizing electrolyte comprises ions selected from the group consisting of dichromate, sulfate, phosphate, nitrate and mixtures thereof.
Claim 15
Dependent Claim
31 words
The article of claim 13 wherein the source of fluoride ion is selected from the group consisting of hydrogen fluoride, sodium fluoride, potassium fluoride, ammomium fluoride, ammonium bifluoride and mixtures thereof.
Claim 16
Dependent Claim
12 words
The article of claim 6 wherein said oxidizing electrolyte comprises dichromate ions.
Claim 17
Dependent Claim
31 words
The article of claim 15 wherein the source of fluoride ion is selected from the group consisting of hydrogen fluoride, sodium fluoride, potassium fluoride, ammonium fluoride, ammonium bifluoride and mixtures thereof.
Claim 18
Dependent Claim
15 words
The article of claim 1 wherein the pH of said solution is less than 3.
Claim 19
Dependent Claim
87 words
In a process for manufacturing an adhesively bonded titanium structure the improvement wherein the titanium elements to be bonded together are anodized in an aqueous solution comprising fluoride ions and an oxidizing electrolyte, the pH of said solution being less than 6, the anodizing potential being from about 5 to about 40 volts, and the fluoride concentration being such as to result in a current density of from about 0.25 to 5 amperes per square foot, whereby a porous, adhesion-promoting oxide coating is formed on said elements.
Claim 20
Dependent Claim
87 words
In a process for manufacturing an adhesively bonded titanium structure the improvement wherein the titanium elements to be bonded together are anodized in an aqueous solution comprising fluoride ions and an oxidizing electrolyte, the pH of said solution being less than 6, the anodizing potential being from about 5 to about 40 volts, and the fluoride concentration being such as to result in a current density of from about 0.25 to 5 amperes per square foot, whereby a porous, adhesion-promoting oxide coating is formed on said elements.
Claim 21
Dependent Claim
24 words
The process of claim 18 wherein said oxidizing electrolyte comprises ions selected from the group consisting of dichromate, sulfate, phosphate, nitrate and mixtures thereof.
Claim 22
Dependent Claim
31 words
The process of claim 19 wherein the source of fluoride ion is selected from the group consisting of hydrogen fluoride, sodium fluoride, potassium fluoride, ammonium fluoride, ammonium bifluoride and mixtures thereof.
Claim 23
Dependent Claim
12 words
The process of claim 18 wherein said oxidizing electrolyte comprises dichromate ions.
Claim 24
Dependent Claim
31 words
The process of claim 21 wherein the source of fluoride ion is selected from the group consisting of hydrogen fluoride, sodium fluoride, potassium fluoride, ammonium fluoride, ammonium bifluoride and mixtures thereof.
Claim 25
Dependent Claim
31 words
The process of claim 18 wherein the source of fluoride ion is selected from the group consisting of hydrogen fluoride, sodium fluoride, potassium fluoride, ammonium fluoride, ammonium bifluoride and mixtures thereof.
Claim 26
Dependent Claim
20 words
The process of claim 18 wherein the temperature of said solution is from about 50° F. to about 80° F.
Claim 27
Dependent Claim
22 words
The process of claim 18 wherein said current density is maintained at from about 1 to about 3 amperes per square foot.
Claim 28
Dependent Claim
16 words
The process of claim 25 wherein said potential is from about 10 to about 15 volts.
Claim 29
Dependent Claim
24 words
The process of claim 26 wherein said oxidizing electrolyte comprises ions selected from the group consisting of dichromate, sulfate, phosphate, nitrate and mixtures thereof.
Claim 30
Dependent Claim
31 words
The process of claim 27 wherein the source of fluoride ion is selected from the group consisting of hydrogen fluoride, sodium fluoride, potassium fluoride, ammonium fluoride, ammonium bifluoride and mixtures thereof.
Claim 31
Dependent Claim
12 words
The process of claim 26 wherein said oxidizing electrolyte comprises dichromate ions.
Claim 32
Dependent Claim
31 words
The process of claim 29 wherein the source of fluoride ion is selected from the group consisting of hydrogen fluoride, sodium fluoride, potassium fluoride, ammonium fluoride, ammonium bifluoride and mixtures thereof.
Claim 33
Dependent Claim
15 words
The process of claim 18 wherein the pH of said solution is less than 3.
Claim 34
Dependent Claim
17 words
The process of claim 18 wherein said anodizing potential is from about 7.5 to about 20 volts.
Claim 35
Dependent Claim
17 words
The process of claim 18 wherein said anodizing potential is from about 10 to about 15 volts.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-11-02 | 1980-05-03 | 1980-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-02 | 1984-05-03 | 1984-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-02 | 1988-05-03 | 1988-11-02 | $7700.00 | Window Closed / Lapsed |