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US5356492A Expired / Lapsed US ⏱️ 0.0 years remaining

Non-toxic corrosion resistant conversion process coating for aluminum and aluminum alloys

Assignee: Lockheed Martin Corp
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Filing: 1993-04-30
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Granted: 1994-10-18
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Expires: 2013-04-30
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Abstract

Abstract A non-toxic corrosion resistant conversion coating process for aluminum and aluminum alloys which includes subjecting the aluminum to an aqueous solution containing hydrogen peroxide or 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 17:16
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/05; C23C22/06; C23C22/48; C23C22/56; C23C22/82; C23C22/83; C23C2222/00; C23C2222/20

Claims Analysis

Total Claims: 16
Claim 1
Independent Claim 46 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 aqueous solution containing cerous chloride and hydrogen peroxide wherein an acidic condition is created by the hydrolysis of the cerous chloride.
Claim 2
Dependent Claim 46 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 aqueous solution containing cerous chloride and hydrogen peroxide wherein an acidic condition is created by the hydrolysis of the cerous chloride.
Claim 3
Dependent Claim 16 words
The process of claim 1 wherein the aqueous solution created as aforesaid further contains strontium chloride.
Claim 4
Dependent Claim 45 words
The process of claim 1 followed by a thorough rinsing of the treated aluminum aforesaid and then subjecting said treated aluminum to a solution containing ethyl alcohol, phenyltrimethoxysilane and glycidoxy(epoxy)polyfunctionalmethoxysilane whereby the coating thus produced on said aluminum combines water repellency with good paint adherence.
Claim 5
Dependent Claim 44 words
The process of claim 1 followed by a thorough rinsing of the treated aluminum aforesaid and then subjecting said treated aluminum to a solution containing ethyl alcohol and glycidoxy(epoxy)polyfunctionalmethoxysilane whereby the coating thus produced on said aluminum combines water repellency with good paint adherence.
Claim 6
Dependent Claim 36 words
The process of claim 1 followed by a thorough rinsing of the treated aluminum aforesaid and then subjecting said treated aluminum to a solution containing sodium molybdate, sodium nitrite and sodium metasilicate at about 200° F.
Claim 7
Dependent Claim 45 words
The process of claim 2 followed by a thorough rinsing of the treated aluminum aforesaid and then subjecting said treated aluminum to a solution containing ethyl alcohol, phenyltrimethoxysilane and glycidoxy(epoxy)polyfunctionalmethoxysilane whereby the coating thus produced on said aluminum combines water repellency with good paint adherence.
Claim 8
Dependent Claim 44 words
The process of claim 2 followed by a thorough rinsing of the treated aluminum aforesaid and then subjecting said treated aluminum to a solution containing ethyl alcohol and glycidoxy(epoxy)polyfunctionalmethoxysilane whereby the coating thus produced on said aluminum combines water repellency with good paint adherence.
Claim 9
Dependent Claim 33 words
The process of claim 2 followed by a thorough rinsing of said aluminum and then subjecting said aluminum to a solution containing sodium molybdate, sodium nitrite and sodium metasilicate at about 200° F.
Claim 10
Dependent Claim 47 words
The process of claim 1 followed by a thorough rinsing of said aluminum, then subjecting said aluminum to an aqueous solution containing sodium molybdate, sodium nitrite and sodium metasilicate and finally after a thorough rinsing said aluminum is subjected to a solution containing alcohol, phenyltrimethoxysilane and glycidoxy(epoxy)polyfunctionalmethoxysilane.
Claim 11
Dependent Claim 45 words
The process of claim 1 followed by a thorough rinsing of said aluminum, then subjecting said aluminum to an aqueous solution containing sodium molybdate, sodium nitrite and sodium metasilicate and finally after thoroughly rinsing said aluminum is subjected to a solution containing alcohol and glycidoxy(epoxy)polyfunctionalmethoxysilane.
Claim 12
Dependent Claim 51 words
The process of claim 2 followed by a thorough rinsing of said aluminum, then subjecting said aluminum to an aqueous solution containing sodium molybdate, sodium nitrite and sodium metasilicate at about 200° F. and finally after a thorough rinsing said aluminum is subjected to a solution containing alcohol, phenytrimethoxysilane and glycidoxy(epoxy)polyfunctionalmethoxysilane.
Claim 13
Dependent Claim 49 words
The process of claim 2 followed by a thorough rinsing of said aluminum, then subjecting said aluminum to an aqueous solution containing sodium molybdate, solidum nitrite and sodium metasilicate at about 200° F. and finally after thoroughly rinsing said aluminum is subjected to a solution containing alcohol and glycidoxy(epoxy)polyfunctionalmethoxysilane.
Claim 14
Dependent Claim 56 words
A process for producing a corrosion resistant chemical conversion coating on aluminum and aluminum alloys comprising subjecting a cleaned and deoxidized aluminum surface to an aqueous solution containing sodium molybdate, sodium nitrite and sodium metasilicate at about 200 degrees F. and then subjecting said treated aluminum to an aqueous solution containing cerous chloride and hydrogen peroxide.
Claim 15
Dependent Claim 56 words
A process for producing a corrosion resistant chemical conversion coating on aluminum and aluminum alloys comprising subjecting a cleaned and deoxidized aluminum surface to an aqueous solution containing sodium molybdate, sodium nitrite and sodium metasilicate at about 200 degrees F. and then subjecting said treated aluminum to an aqueous solution containing cerous chloride and hydrogen peroxide.
Claim 16
Dependent Claim 19 words
The process of claim 13 wherein the solution which contains cerous chloride and hydrogen peroxide also contains strontium chloride.

References Cited (Backward Citations)

US4610732A Cited
US5194138A Cited
US5192374A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-10-17 1998-04-18 1998-10-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-10-17 2002-04-18 2002-10-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-10-17 2006-04-18 2006-10-18 $7700.00 Window Closed / Lapsed

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