Patent US3620939A successfully refreshed from Google Patents.
US3620939A
Expired / Lapsed
US
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Coating for magnesium and its alloys and method of applying
Assignee: United States Department of the Army
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Filing: 1969-03-17
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Granted: 1971-11-16
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Expires: 1989-03-17
Abstract
Abstract The surface of magnesium and its alloys is provided with a protective coating, both decorative and resistant to corrosion, when subjected to an ammonium bifluoride and an ammonium metavanadate aqueous solution which preferably contains in addition water-soluble organic compounds, water-soluble permanganate ions, or water-soluble nitrate ions. The coating is conveniently and efficiently applied to the metal which is the anode in the coating solution.
Inventors
- 👤 Ocke C Fruchtnicht
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:53
CPC Classifications
C; C25; C25D; C25D9/00; C25D9/04; C25D9/06
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
81 words
Method of claim 1 and wherein said surface prior to being subjected to anodic reactions is subjected to vapor degreasing and cleaning; said aqueous bath comprises ammonium bifluoride about 42 ounces/gallon, ammonium metavanadate about 11 ounces/gallon, and an additional ingredient selected from the polar compounds consisting of ethanol, sodium potassium tartrate, citric acid, ethylene glycol, dimethylsulfoxide, N,N-dimethylformamide, dimethylenetriamine, ethanolamine, allyl alcohol, piperidine, potassium permanganate, sodium permanganate, sodium nitrate, and potassium nitrate in an amount from about 2.5 to about 30 ounces/gallon.
Claim 2
Dependent Claim
92 words
Method of claim 2 and wherein said surface is vapor degreased in trichloroethylene and said cleaning is done by acid etching in a bath constituted of about 8 fluid ounces of nitric acid, 2 fluid ounces of sulfuric acid, and 90 ounces of distilled water; said impressed potential of a predetermined value of volts is in the range of approximately 135-190 volts; said predetermined value of current density is about 24 a./square foot; said predetermined time is from about 10 to about 20 minutes; and said protective coating formed is corrosion resistant.
Claim 3
Dependent Claim
24 words
Method of claim 3 and wherein said impressed potential of a predetermined value of volts is in the range of approximately 140-190 AC volts.
Claim 4
Dependent Claim
44 words
Method of claim 4 and wherein said impressed potential of about 150 AC volts is reached in about 10 minutes and said volts are allowed to remain for about an additional 10 minutes during which time said current density drops to about zero value.
Claim 5
Dependent Claim
45 words
Method of claim 3 and wherein said impressed potential of about 150 DC volts is reached in about 10 minutes and said volts are allowed to remain for about an additional 10 minutes during which time the said current density drops to about zero value.
Claim 6
Dependent Claim
23 words
An article of magnesium and its alloys covered with a decorative and protective coating as set forth in the method of claim 1.
Claim 7
Dependent Claim
37 words
An article of magnesium and its alloys covered with a decorative and protective coaTing as set forth in the method of claim 2 and wherein said additional ingredient is ethanol in an amount of 32 fluid ounces/gallon.
Claim 8
Dependent Claim
53 words
An article of magnesium and its alloys covered with a decorative and protective coating as set forth in the method of claim 2 and wherein said additional ingredient is selected from potassium permanganate, sodium potassium tartrate, and citric acid in an amount of about 4 grams per 200 milliliters of said aqueous bath.
Claim 9
Dependent Claim
59 words
An article of magnesium and its alloys covered with a decorative and protective coating as set forth in the method of claim 2 and wherein said additional ingredient is selected from ethylene glycol, dimethylsulfoxide, N,N-dimethylformamide, diethylenetriamine ethanolamine, allyl alcohol and piperidine in an amount from about 10 milliliters to about 20 milliliters per 200 milliliters of said aqueous bath.
Claim 10
Dependent Claim
43 words
An aqueous solution for anodizing magnesium and its alloys comprising ammonium bifluoride in an amount in the range of 32 oz. to 52 oz. per gallon and ammonium meta-vanadate in an amount in the range of 8 oz. to 14 oz. per gallon.
Claim 11
Dependent Claim
84 words
The aqueous solution of claim 11 and wherein said ammonium bifluoride is present in an amount of 42 oz. per gallon, ammonium meta-vanadate is in an amount of 11 oz. per gallon, and an additional ingredient is present in an amount from about 2.5 oz. to about 30 oz./gallon; said additional ingredient being selected from the polar compounds consisting of ethanol, sodium potassium tartrate, citric acid, ethylene glycol, dimethylsulfoxide, N,N-dimethylformamide, dimethylenetriamine, ethanolamine, allyl alcohol, piperidine, potassium permanganate, sodium permanganate, sodium nitrate, and potassium nitrate.
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) | 1974-11-15 | 1975-05-17 | 1975-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-15 | 1979-05-17 | 1979-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-15 | 1983-05-17 | 1983-11-16 | $7700.00 | Window Closed / Lapsed |