US3907609A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Conversion coating for titanium and titanium base alloys
Assignee: McDonnell Douglas Corp
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Filing: 1974-02-14
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Granted: 1975-09-23
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Expires: 1994-02-14
Abstract
Abstract This application discloses a chemical conversion process and composition for producing an adherent conversion coating on titanium and its alloys. The composition comprises a combination of sodium hydroxide and a hexavalent chromium compound. The process comprises the treatment of the titanium part with the usual, well-known nitric-hydrofluoric acid solution and/or an alkaline cleaner to obtain a clean surface. Then the parts are exposed to the process of this application which produces a surface resulting in increased adhesion or retention of subsequently applied coatings such as chemical milling maskants, adhesive bonding materials, lubricants, other protective coatings, and enhances the adhesion of composite materials to titanium.
Inventors
- 👤 Dolphus Larry Coggins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:48
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/60; C23C22/64
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
13 words
about 9 to about 36 percent by weight of an alkali metal hydroxide;
Claim 2
Dependent Claim
13 words
about 9 to about 36 percent by weight of an alkali metal hydroxide;
Claim 3
Dependent Claim
57 words
A solution for treating the surfaces of articles of titanium and titanium base alloys so that coatings will effectively bond to the surfaces thereof consisting essentially of: A. about 9 to about 36 percent by weight of an alkali metal hydroxide; B. about 0.08 to about 6 percent by weight of hexavalent chromium ions; and C. water.
Claim 4
Dependent Claim
57 words
A solution for treating the surfaces of articles of titanium and titanium base alloys so that coatings will effectively bond to the surfaces thereof consisting essentially of: A. about 9 to about 36 percent by weight of an alkali metal hydroxide; B. about 0.08 to about 6 percent by weight of hexavalent chromium ions; and C. water.
Claim 5
Dependent Claim
13 words
The composition of claim 1 wherein said alkali metal hydroxide is sodium hydroxide.
Claim 6
Dependent Claim
13 words
about 0.08 to about 6 percent by weight of a hexavalent chromium compound.
Claim 7
Dependent Claim
13 words
about 0.08 to about 6 percent by weight of a hexavalent chromium compound.
Claim 8
Dependent Claim
37 words
The composition of claim 1 wherein said hexavalent chromium ions came from a compound selected from a group consisting of sodium dichromate, potassium dichromate, various chromic oxides, zinc chromate, copper chromate and chromium acetate and mixtures thereof.
Claim 9
Independent Claim
64 words
A METHOD OF TREATING THE SURFACES OF ARTICLES OF TITANIUM AND TITANIUM BASE ALLOYS SO THAT COATINGS WILL EFFECTIVELY BOND TO THE SURFACE THEREOF, WHICH COMPRISES CONTACTING SAID ARTICLES WITH A SOLUTION CONSISTING ESSENTIALLY OF: A. ABOUT 9 TO ABOUT 36 PERCENT BY WEIGHT OF AN ALKALI METAL HYDROXIDE: AND B. ABOUT 0.08 TO ABOUT 6 PERCENT BY WEIGHT OF A HEXAVALENT CHROMIUM COMPOUND.
Claim 10
Independent Claim
64 words
A METHOD OF TREATING THE SURFACES OF ARTICLES OF TITANIUM AND TITANIUM BASE ALLOYS SO THAT COATINGS WILL EFFECTIVELY BOND TO THE SURFACE THEREOF, WHICH COMPRISES CONTACTING SAID ARTICLES WITH A SOLUTION CONSISTING ESSENTIALLY OF: A. ABOUT 9 TO ABOUT 36 PERCENT BY WEIGHT OF AN ALKALI METAL HYDROXIDE: AND B. ABOUT 0.08 TO ABOUT 6 PERCENT BY WEIGHT OF A HEXAVALENT CHROMIUM COMPOUND.
Claim 11
Dependent Claim
20 words
The method of claim 4 wherein said articles are immersed in said solution for about 1/2 to about 20 minutes.
Claim 12
Dependent Claim
16 words
The method of claim 4 wherein said solution is maintained at about 75* to about 250*F.
Claim 13
Independent Claim
44 words
A method of treating the surfaces of articles of titanium and titanium base alloys so that coatings will effectively bond to the surfaces thereof comprising the steps of A. cleaning the article, B. immersing the cleaned articles surface in a composition consisting essentially of:
Claim 14
Independent Claim
44 words
A method of treating the surfaces of articles of titanium and titanium base alloys so that coatings will effectively bond to the surfaces thereof comprising the steps of A. cleaning the article, B. immersing the cleaned articles surface in a composition consisting essentially of:
Claim 15
Dependent Claim
20 words
The method of claim 7 wherein said articles are immersed in said solution of about 1/2 to about 30 minutes.
Claim 16
Dependent Claim
16 words
The method of claim 7 wherein said solution is maintained at about 75* to about 250*F.
Claim 17
Dependent Claim
41 words
The method of claim 9 wherein the cleaning solution is a nitric-hydrofluoric acid bath comprising about 20 to about 50 percent by weight nitric acid (40* Be) and about 1 to about 10 percent by weight of 70 percent hydrofluoric acid.
References Cited (Backward Citations)
US3706603A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-22 | 1979-03-24 | 1979-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-22 | 1983-03-24 | 1983-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-22 | 1987-03-24 | 1987-09-23 | $7700.00 | Window Closed / Lapsed |