US5399210A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Non-toxic corrosion resistant conversion coating for aluminum and aluminum alloys and the process for making the same
Assignee: Lockheed Martin Corp
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Filing: 1993-02-03
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Granted: 1995-03-21
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Expires: 2013-02-03
Abstract
Abstract A non-toxic corrosion resistant conversion coating for aluminum is formed by a process which includes subjecting the aluminum to an acidic aqueous solution containing potassium permanganate and cerous chloride, alone or in combination with strontium chloride. The corrosion resistance is improved by a subsequent treatment in an alkaline solution containing molybdate, nitrite and metasilicate ions. The corrosion resistant is further improved by treating the coated surface with an acholic solution containing glycidoxy(epoxy)polyfunctionalmethoxysilane, alone or in combination with phenyltrimethoxysilane. The coating thus produced is a mixture of oxides and hydroxides of cerium strontium and aluminum. These oxides and hydroxides may also be intermixed with molybdate silicate and nitrite ions. In the most corrosion resistant form the mixture further includes a silane overcoat.
Inventors
- 👤 Robert N. Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:15
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/82; C23C22/83; C23C22/05; C23C22/06; C23C22/48; C23C22/56; C23C22/60; C23C22/66; C23C2222/00; C23C2222/20
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
35 words
A process for producing a corrosion resistant chemical conversion coating on aluminum and aluminum alloys comprising subjecting a cleaned, degreased and deoxidized aluminum to an alkaline solution containing sodium molybdate, sodium nitrite and sodium metasilicate.
Claim 2
Dependent Claim
35 words
A process for producing a corrosion resistant chemical conversion coating on aluminum and aluminum alloys comprising subjecting a cleaned, degreased and deoxidized aluminum to an alkaline solution containing sodium molybdate, sodium nitrite and sodium metasilicate.
Claim 3
Dependent Claim
52 words
The process of claim 1 followed by a thorough rinsing of said aluminum, then subjecting said aluminum to an acidic aqueous solution containing cerous chloride and potassium permanganate, then following a thorough rinsing of said aluminum subjecting said aluminum to an a aqueous solution containing sodium molybdate, sodium nitrate and sodium metasilicate.
Claim 4
Dependent Claim
47 words
The process of claim 1 followed by a thorough rinsing of said aluminum, then subjecting said aluminum to an acidic aqueous solution containing cerous chloride and potassium permanganate, then following a thorough rinsing of said aluminum subjecting said aluminum to a solution containing alcohol, phenyltrimethoxysilane and glycidoxy(epoxy)polyfunctionalmethoxysilane.
Claim 5
Dependent Claim
46 words
The process of claim 1 followed by a thorough rinsing of said aluminum, then subjecting said aluminum to an acidic aqueous solution containing cerous chloride and potassium permanganate, then following a thorough rinsing of said aluminum subjecting said aluminum to a solution containing alcohol and glycidoxy(epoxy)polyfunctionalmethoxysilane.
Claim 6
Dependent Claim
71 words
The process of claim 1 followed by a thorough rinsing of said aluminum, then subjecting said aluminum to an acidic aqueous solution containing cerous chloride, strontium chloride and potassium permanganate, then following a thorough rinsing of said aluminum subjecting said aluminum to a solution containing sodium molybdate, sodium nitrite and sodium metasilicate, then following a thorough rinsing of said aluminum subjecting such aluminum to a solution containing alcohol, phenyltrimethoxysilane and glycidoxy(epoxy)polyfunctionalmethoxysilane.
Claim 7
Dependent Claim
70 words
The process of claim 1 followed by a thorough rinsing of said aluminum, then subjecting said aluminum to an acidic aqueous solution containing cerous chloride, strontium chloride and potassium permanganate, then following a thorough rinsing of said aluminum subjecting said aluminum to a solution containing sodium molybdate, sodium nitrite and sodium metasilicate, then following a thorough rinsing of said aluminum subjecting said aluminum to a solution containing alcohol and glycidoxy(epoxy)polyfunctionalmethoxysilane.
References Cited (Backward Citations)
US4683157A
Cited
US4711667A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-03-20 | 1998-09-19 | 1999-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-03-20 | 2002-09-19 | 2003-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-03-20 | 2006-09-19 | 2007-03-21 | $7700.00 | Window Closed / Lapsed |