US4085012A
Expired / Lapsed
US
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Method for providing environmentally stable aluminum surfaces for adhesive bonding and product produced
Assignee: Boeing Co
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Filing: 1976-02-26
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Granted: 1978-04-18
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Expires: 1996-02-26
Abstract
Abstract Environmentally stable bond joints of aluminum metal and aluminum alloys in adhesively joined structures are formed by utilizing a prebonding anodization of the aluminum surfaces in a phosphoric acid electrolyte containing from about 1.5 to about 50% H 3 PO 4 at 1 to 50 volts for a period of 5 to 60 minutes using a bath temperature of 50° to 100° F. The anodized surface is then washed free of electrolyte, dried and coated with an adhesive resin. The aluminum metal segments are then arranged in a composite arrangement and bonded together under pressure and heat to cure the adhesive resin. The resulting structure is resistant to failure of the bond joints on exposure to moist atmospheric conditions. The surface preparation provides a hydration resistant aluminum oxide surface which minimizes adhesive-aluminum separation under aqueous exposure. Alloys containing copper and other alloying constituents may be successfully anodized and bonded by this process.
Inventors
- 👤 J. Arthur Marceau
- 👤 Ralph H. Firminhac
- 👤 Yukimori Moji
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:17
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/02; C25D11/04; C25D11/18; C25D11/06; C25D11/08; H; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/05; H05K1/053
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
110 words
A method of preparing an adhesively bonded aluminum structure comprising forming a porous columnar aluminum oxide coating on surfaces of aluminum alloy articles, said aluminum alloy articles containing about 1.6 to about 4.5% by weight copper by anodizing said articles in an aqueous solution comprising phosphoric acid, the anodizing potential being from about 3 to about 25 volts, the phosphoric acid concentration being about 3 to about 20% by weight and the temperature of said solution being from about 50° F. to about 85° F.; rinsing said articles to remove said solution; applying an adhesive to said surfaces; and bonding said aluminum articles together to form said adhesively bonded structure.
Claim 2
Independent Claim
110 words
A method of preparing an adhesively bonded aluminum structure comprising forming a porous columnar aluminum oxide coating on surfaces of aluminum alloy articles, said aluminum alloy articles containing about 1.6 to about 4.5% by weight copper by anodizing said articles in an aqueous solution comprising phosphoric acid, the anodizing potential being from about 3 to about 25 volts, the phosphoric acid concentration being about 3 to about 20% by weight and the temperature of said solution being from about 50° F. to about 85° F.; rinsing said articles to remove said solution; applying an adhesive to said surfaces; and bonding said aluminum articles together to form said adhesively bonded structure.
Claim 3
Dependent Claim
16 words
The method of claim 1 wherein said alumimum alloy article consists of aluminum alloy 7075. --
Claim 4
Dependent Claim
15 words
The method of claim 1 wherein said aluminum alloy article consists of aluminum alloy 2024.--
Claim 5
Dependent Claim
12 words
The method of claim 1 wherein said temperature range is 75°±10° F.--
Claim 6
Dependent Claim
23 words
The process of claim 1 wherein said porous oxide coating is primed with an epoxy resin primer prior to application of said adhesive.
Claim 7
Dependent Claim
160 words
A process for preparing an adhesively bonded structure of copper-containing aluminum alloy adherends wherein said adherends have a polymer receptive aluminum oxide surface thereon having a porous columnar structure with a thickness of from about 500 to about 600 Angstroms, having pores from about 300 to about 600 Angstroms in diameter and from about 400 to about 5000 Angstroms in depth extending into said oxide surface, said structure prepared by the steps of: cleaning and deoxidizing said adherends; anodizing said adherends in an aqueous phosphoric acid solution containing from about 3 to about 20% by weight H 3 PO 4 at a temperature of from about 50 to about 85° F. for about 10 to about 30 minutes at a potential of about 3 to about 25 volts; rinsing said adherends to remove said aqueous phosphoric acid solution; applying an adhesive to the surface of at least one of said adherends; and bonding said adherends together to form said structure.
Claim 8
Dependent Claim
160 words
A process for preparing an adhesively bonded structure of copper-containing aluminum alloy adherends wherein said adherends have a polymer receptive aluminum oxide surface thereon having a porous columnar structure with a thickness of from about 500 to about 600 Angstroms, having pores from about 300 to about 600 Angstroms in diameter and from about 400 to about 5000 Angstroms in depth extending into said oxide surface, said structure prepared by the steps of: cleaning and deoxidizing said adherends; anodizing said adherends in an aqueous phosphoric acid solution containing from about 3 to about 20% by weight H 3 PO 4 at a temperature of from about 50 to about 85° F. for about 10 to about 30 minutes at a potential of about 3 to about 25 volts; rinsing said adherends to remove said aqueous phosphoric acid solution; applying an adhesive to the surface of at least one of said adherends; and bonding said adherends together to form said structure.
Claim 9
Dependent Claim
18 words
The process of claim 6 wherein said adherends contain from about 1.6 to about 4.5% by weight copper.
Claim 10
Dependent Claim
13 words
The process of claim 6 wherein said adherends consist of aluminum alloy 2024.
Claim 11
Dependent Claim
13 words
The process of claim 6 wherein said adherends consist of aluminum alloy 7075.
Claim 12
Dependent Claim
12 words
The process of claim 6 wherein said temperature range is 75°±10° F.
Claim 13
Dependent Claim
33 words
The process of claim 6 wherein said temperature is about 70° F, said solution contains about 10% phosphoric acid, said potential is about 10 volts and said anodization time is about 20 minutes.
Claim 14
Dependent Claim
25 words
The process of claim 6 wherein said oxide surface is coated with an epoxy primer and adhered to another surface with an epoxy resin adhesive.
Claim 15
Dependent Claim
23 words
The process of claim 6 wherein said porous oxide coating is primed with an epoxy resin primer prior to application of said adhesive.
Claim 16
Dependent Claim
154 words
An adhesively bonded alumimum alloy structure formed by adhesively bonding together aluminum adherends containing from about 1.6 to about 4.5% by weight copper, said adherends each having a polymer receptive aluminum oxide surface thereon having a porous columnar structure with a thickness of from about 500 to about 6000 Angstroms, having pores from about 300 to about 600 Angstroms in diameter and from about 400 to about 5000 Angstroms in depth extending into said oxide surface, said structure prepared by anodizing the surfaces of said adherends in an aqueous phosphoric acid solution containing from about 3 to about 20% by weight H 3 PO 4 at a temperature of from about 50° F. to about 85° F. for about 10 to about 30 minutes at a potential of from about 3 to about 25 volts, rinsing said adherends to remove said solution, applying a polymeric adhesive to said surfaces and bonding said adherends together.
Claim 17
Dependent Claim
154 words
An adhesively bonded alumimum alloy structure formed by adhesively bonding together aluminum adherends containing from about 1.6 to about 4.5% by weight copper, said adherends each having a polymer receptive aluminum oxide surface thereon having a porous columnar structure with a thickness of from about 500 to about 6000 Angstroms, having pores from about 300 to about 600 Angstroms in diameter and from about 400 to about 5000 Angstroms in depth extending into said oxide surface, said structure prepared by anodizing the surfaces of said adherends in an aqueous phosphoric acid solution containing from about 3 to about 20% by weight H 3 PO 4 at a temperature of from about 50° F. to about 85° F. for about 10 to about 30 minutes at a potential of from about 3 to about 25 volts, rinsing said adherends to remove said solution, applying a polymeric adhesive to said surfaces and bonding said adherends together.
Claim 18
Dependent Claim
12 words
The structure of claim 14 wherein said temperature range is 75±10° F.
Claim 19
Dependent Claim
35 words
The structure of claim 14 wherein said temperature is about 70° F., said solution contains about 10% by weight phosporic acid, said potential is about 10 volts and said anodization time is about 20 minutes.
Claim 20
Dependent Claim
35 words
The structure of claim 14 wherein said temperature is about 70° F., said solution contains about 10% by weight phosphoric acid, said potential is about 10 volts and said anodization time is about 20 minutes.
Claim 21
Dependent Claim
23 words
The process of claim 14 wherein said porous oxide coating is primed with an epoxy resin primer prior to application of said adhesive.
Claim 22
Independent Claim
154 words
A method of preparing an adhesively bonded aluminum structure comprising: forming a porous oxide coating on surfaces of aluminum articles, said oxide coating being a polymer receptive, substantially unhydrated aluminum oxide having a porous columnar structure with a thickness of from about 500 to about 6000 Angstroms, having pores from about 300 to about 600 Angstroms in diameter and from about 400 to about 5,000 Angstroms in depth extending into said oxide surface, by anodizing said articles in an aqueous acidic solution, the acid component thereof consisting essentially of phosphoric acid, the anodizing potential being from about 3 to about 25 volts, the phosphoric acid concentration being about 3 to about 20% by weight and the temperature of said solution being from about 50° F. to about 85° F.; rinsing said articles to remove said solution; applying an adhesive to said surfaces; and bonding said aluminum articles together to form said adhesively bonded structure.
Claim 23
Independent Claim
154 words
A method of preparing an adhesively bonded aluminum structure comprising: forming a porous oxide coating on surfaces of aluminum articles, said oxide coating being a polymer receptive, substantially unhydrated aluminum oxide having a porous columnar structure with a thickness of from about 500 to about 6000 Angstroms, having pores from about 300 to about 600 Angstroms in diameter and from about 400 to about 5,000 Angstroms in depth extending into said oxide surface, by anodizing said articles in an aqueous acidic solution, the acid component thereof consisting essentially of phosphoric acid, the anodizing potential being from about 3 to about 25 volts, the phosphoric acid concentration being about 3 to about 20% by weight and the temperature of said solution being from about 50° F. to about 85° F.; rinsing said articles to remove said solution; applying an adhesive to said surfaces; and bonding said aluminum articles together to form said adhesively bonded structure.
Claim 24
Dependent Claim
12 words
The method of claim 19 wherein said temperature range is 75°±10° F.-
Claim 25
Dependent Claim
11 words
The method of claim 19 wherein said potential is 10±1 volts.
Claim 26
Dependent Claim
14 words
The method of claim 19 wherein said phosphoric acid concentration is 10±2% by weight.
Claim 27
Dependent Claim
16 words
The method of claim 19 wherein said anodization is conducted for from 10 to 30 minutes.
Claim 28
Dependent Claim
23 words
The process of claim 19 wherein said porous oxide coating is primed with an epoxy resin primer prior to application of said adhesive.
Claim 29
Dependent Claim
163 words
An adhesively bonded structure formed by bonding together aluminum adherends, each adhered having a polymer receptive hydration-resistant, aluminum oxide surface thereon, said oxide surface having a porous columnar structure with a thickness of from about 500 to about 6,000 Angstroms, having pores from about 300 to about 600 Angstroms in diameter and from about 400 to about 5,000 Angstroms in depth extending into said oxide surface, said surface prepared by anodizing the surface of said adherend in an aqueous acidic electrolyte, the acidic component of said electrolyte consisting essentially of H 3 PO 4 present in amounts from about 3 to about 20% by weight H 3 PO 4 at a temperature of from about 60° F. to about 90° F. for about 10 to about 30 minutes at a potential of from about 3 to about 25 volts, rinsing said adherend to remove said solution, applying an adhesive to said surfaces and bonding said adherends together to form said adhesively bonded structure.
Claim 30
Dependent Claim
163 words
An adhesively bonded structure formed by bonding together aluminum adherends, each adhered having a polymer receptive hydration-resistant, aluminum oxide surface thereon, said oxide surface having a porous columnar structure with a thickness of from about 500 to about 6,000 Angstroms, having pores from about 300 to about 600 Angstroms in diameter and from about 400 to about 5,000 Angstroms in depth extending into said oxide surface, said surface prepared by anodizing the surface of said adherend in an aqueous acidic electrolyte, the acidic component of said electrolyte consisting essentially of H 3 PO 4 present in amounts from about 3 to about 20% by weight H 3 PO 4 at a temperature of from about 60° F. to about 90° F. for about 10 to about 30 minutes at a potential of from about 3 to about 25 volts, rinsing said adherend to remove said solution, applying an adhesive to said surfaces and bonding said adherends together to form said adhesively bonded structure.
Claim 31
Dependent Claim
12 words
The structure of claim 25 wherein said temperature range is 75°±10° F
Claim 32
Dependent Claim
23 words
The process of claim 25 wherein said porous oxide coating is primed with an epoxy resin primer prior to application of said adhesive.
Claim 33
Dependent Claim
134 words
A process for preparing an adhesively bonded aluminum structure from aluminum adherends comprising the steps of: cleaning the surface of said adherends; deoxidizing the surface of said adherends; forming a porous aluminum oxide surface on said adherends by anodization of said adherends in an aqueous acidic solution, the acidic component thereof consisting essentially of phosphoric acid, the anodizing potential being from about 3 to about 25 volts, the phosphoric acid concentration being about 3 to about 20% by weight, the temperature of said solution being in the range of 75°±10° F.; rinsing said adherends to remove said solution; applying an epoxy resin primer to said porous aluminum oxide surface; curing said primer; applying an adhesive to at least one of said adherends; and bonding said adherends together to form said adhesively bonded aluminum structure.
Claim 34
Dependent Claim
134 words
A process for preparing an adhesively bonded aluminum structure from aluminum adherends comprising the steps of: cleaning the surface of said adherends; deoxidizing the surface of said adherends; forming a porous aluminum oxide surface on said adherends by anodization of said adherends in an aqueous acidic solution, the acidic component thereof consisting essentially of phosphoric acid, the anodizing potential being from about 3 to about 25 volts, the phosphoric acid concentration being about 3 to about 20% by weight, the temperature of said solution being in the range of 75°±10° F.; rinsing said adherends to remove said solution; applying an epoxy resin primer to said porous aluminum oxide surface; curing said primer; applying an adhesive to at least one of said adherends; and bonding said adherends together to form said adhesively bonded aluminum structure.
Claim 35
Dependent Claim
9 words
The product produced by the process of claim 28.
References Cited (Backward Citations)
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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) | 1981-04-17 | 1981-10-17 | 1982-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-17 | 1985-10-17 | 1986-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-17 | 1989-10-17 | 1990-04-18 | $7700.00 | Window Closed / Lapsed |