US3039898A - Coating aluminum surfaces - Google Patents
Coating aluminum surfaces Download PDFInfo
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- US3039898A US3039898A US86866A US8686661A US3039898A US 3039898 A US3039898 A US 3039898A US 86866 A US86866 A US 86866A US 8686661 A US8686661 A US 8686661A US 3039898 A US3039898 A US 3039898A
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- US
- United States
- Prior art keywords
- oxide
- coating
- aluminum
- magnesium oxide
- solution
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 title claims description 36
- 238000000576 coating method Methods 0.000 title claims description 36
- 229910052782 aluminium Inorganic materials 0.000 title claims description 35
- 239000011248 coating agent Substances 0.000 title claims description 26
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 claims description 24
- 239000000395 magnesium oxide Substances 0.000 claims description 24
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 claims description 24
- 238000000034 method Methods 0.000 claims description 13
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 8
- 238000009877 rendering Methods 0.000 claims description 2
- 239000010408 film Substances 0.000 description 21
- 239000000243 solution Substances 0.000 description 21
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 4
- 150000001875 compounds Chemical class 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 238000009835 boiling Methods 0.000 description 3
- 230000015556 catabolic process Effects 0.000 description 3
- 238000005260 corrosion Methods 0.000 description 3
- 230000007797 corrosion Effects 0.000 description 3
- 238000007654 immersion Methods 0.000 description 3
- 150000004682 monohydrates Chemical class 0.000 description 3
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 230000002035 prolonged effect Effects 0.000 description 2
- 239000011253 protective coating Substances 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 241000382509 Vania Species 0.000 description 1
- 230000002745 absorbent Effects 0.000 description 1
- 239000002250 absorbent Substances 0.000 description 1
- MQRWBMAEBQOWAF-UHFFFAOYSA-N acetic acid;nickel Chemical compound [Ni].CC(O)=O.CC(O)=O MQRWBMAEBQOWAF-UHFFFAOYSA-N 0.000 description 1
- 230000001154 acute effect Effects 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 239000010407 anodic oxide Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000002848 electrochemical method Methods 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- AWJWCTOOIBYHON-UHFFFAOYSA-N furo[3,4-b]pyrazine-5,7-dione Chemical compound C1=CN=C2C(=O)OC(=O)C2=N1 AWJWCTOOIBYHON-UHFFFAOYSA-N 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229940078494 nickel acetate Drugs 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical class O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- BQEYWCOGTSYIEI-UHFFFAOYSA-M sodium;carbonic acid;hydroxy-oxido-dioxochromium Chemical compound [Na+].OC(O)=O.O[Cr]([O-])(=O)=O BQEYWCOGTSYIEI-UHFFFAOYSA-M 0.000 description 1
- 238000010186 staining Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
- C23C22/60—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using alkaline aqueous solutions with pH greater than 8
- C23C22/66—Treatment of aluminium or alloys based thereon
Definitions
- This invention relates to the treatment of aluminum surfaces, and more particularly to an improved method for imparting a protective coating or film to such surfaces.
- This application is a continuation-in-part of our co-pending applications Serial Nos. 852,932 and 30,430, filed November 16, 1959, and May 20, 1960, respectively, both now abandoned.
- the word aluminum includes pure aluminum, commercial aluminum containing the usual impurities, and aluminum base alloys.
- Aluminum surfaces provided with artificial oxide coatings or films may afiord high insulating properties, and increased resistance against corrosion, chemical action and the like.
- Such protective oxide coatings or films may be produced commercially by chemical or electrochemical methods.
- an oxide coating may be produced by treating the aluminum surface with an alkaline solution of a carbonate, usually a sodium carbonate-chromate solution.
- an oxide coating may be produced by the anodic oxidation of the aluminum surface whereby the aluminum is made the anode is an electrolytic solution such as sulfuric acid solution or chromic acid solution.
- oxide coatings formed by these well-known commercial methods are amorphous, relatively porous and absorbent.
- the anodic coatings generally are sealed as by immersing the aluminum article in boiling water or a boiling nickel acetate solution. Sealing renders the oxide coating nonabsorbent thereby minimizing corrosion or staining of the coating.
- it is essential to produce a relatively thick oxide film, and sometimes anodic oxide coatings are made as thick as about one mil or more.
- relatively thick, hard coatings being somewhat brittle, have a tendency to craze as, for example, when Wound in a small radius or bent at an acute angle, and therefore are somewhat limited in applications.
- Oxide films formed in this manner are hard, crystalline films of tic-alumina monohydrate, represented by the formula Al O -H O. Relatively thin conversion films of this nature exhibit high resistance to corrosion or chemical attack and high electrical insulating properties. For most applications, the thickness of the film should not be less than about 0.01 mil. However, use of a-alumina monohydrate surface films has attained only very limited commercial success because of the prolonged treatment required for forming a film of suflicient thickness.
- the increased thickness of the coating is attributable to the presence of hydrated magnesium oxide, often in association with some hydrated aluminum oxides. Coatings of this nature show high electrical insulating properties.
- the hydrated magnesium oxide is generally found present in an amount of at least about 20% by Weight of the coating, and may even comprise the major part of the coating. For suitable electrical insulating applications, the total thickness of the coating should not be less than about 0.1 mil and may be higher.
- the primary object of this invention to provide an improved method of imparting a protective coating or film to an aluminum surface in a relatively short period of time by employing a chemical method.
- an oxide coating may be produced on an aluminum surface by immersing the same-in a Warm or hot solution consisting essentially of water and magnesium oxide, containing not less than about 0.5 gram per liter of magnesium oxide so that such compound is present in the solution in an amount in excess of its solubility in the solution. Solutions of less than about 0.5 gram per liter of magnesium oxide do not produce a coating of the thickness usually desired. On the other hand, generallyno substantial benefit appears to be gained by employing more than about 10 grams per liter of magnesium oxide. For best results, and for relative ease of operation, the solution preferably contains about 3 to 6 grams per liter of magnesium oxide. A dense, crystalline oxide film comprising hydrated magnesium oxide, of thickness ordinarily desired, may be so imparted to the aluminum surface by a single immersion in the solution for at least about 1 minute.
- the solution employed in accordance with our procedure for producing the coating has a pH of not less than about 8.5 and may be as high as 11, a pH above 10 being particularly desirable for carrying out the process in a short period of time.
- a pH above 10 being particularly desirable for carrying out the process in a short period of time.
- treating aluminum surfaces in a solution having a pH lower than approximately 8.5 proceeds too slowly to be economically feasible, particularly for continuous coating operations.
- the alkalinity of the solution normally does not exceed a pH of about 11, any substantial etching action resulting in dissolving away of the aluminum metal and oxide that forms is avoided.
- magnesium oxide is only slightly soluble in water, even at elevated temperatures, the relatively low concentration of the compound in solution renders the aqueous solution alkaline within the pH range found desirable for the practice of our invention, thereby obviating the need for a buffer.
- Magnesium oxide has a maximum solubility of about 0.09 gram per liter in hot water.
- a solution of magnesium oxide has a pH of about 9.5 or higher, at 150 R, which may be readily maintained by the desired excess of undissolved magnesium oxide.
- the desired oxide coating can but be obtained #by treating the aluminum surface in a bath as herein described, which is maintained at a temperature above about -F., and preferably between about F. and 200 F.
- Employing bath temperatu-res lower than about 125 F. extends considerably the time required for producing the oxide coating (or producies undesirably thin films) and, therefore, is not practica
- Immersing an aluminum article in the aqueous solution of magnesium oxide for about 1 to 15 minutes, and preferably 3 to 12 minutes will produce the desired crystalline oxide film, when operating within the above-described temperature ranges. More prolonged immersions may increaseslightly the thickness of oxide coating produced, but this increase generally is not suificient to warrant the longer irnmersions.
- immersions for less than about 1 minute may in some cases be useful, but generally are not sufiicient to produce an oxide surface coating of depth usually desired.
- Aluminum panels treated in accordance with our invention were tested for the DC. voltage breakdown of the oxide coating to determine the insulating properties of the coating.
- the voltage breakdown tester was that developed by the National Bureau of Standards and published in The Review of Scientific Instruments, vol. 24, No. 6, p. 458 (June 1953), employing a one ounce copper probe.
- the coatings of hydrated magnesium oxide formed on the treated panels had thicknesses between about 0.11 to 0.16 mil. The results are set forth in the Aluminum panels having a natural oxide film exhibit an average voltage breakdown of less than 10.
- the hydrated magnesium oxide coating formed on an aluminum surface in accordance with our invention is characterized by high insulating properties.
- Aluminum strip provided with this film is useful, for example, in electrical condensers or foil Wound coils where windings of small radii would not craze the thin oxide film.
- the method of producing an oxide coating on an aluminum surface comprising immersing an aluminum surface, for at least about 1 minute, in a solution maintained at a temperature above about 125 and consisting essentially of water and at least about 0.5 gram per liter of magnesium oxide, said magnesium oxide rendering the solution alkaline within a pH range of approximately 8.5 to 11, whereby a crystalline coating comprising hydrated magnesium oxide is formed on the aluminum surface.
Description
United States Patent 3,039,898 COATING ALUMINUM SURFACES Fred Keller, New Kensington, and Walter G. Zelley, Lower Burrell, Pa., assignors to Aluminum Company of America, Pittsburgh, Pa., a corporation of Pennsyl- Vania No Drawing. Filed Feb. 3, 1961, Ser. No. 86,866 4 Claims. (Cl. 1486.14)
This invention relates to the treatment of aluminum surfaces, and more particularly to an improved method for imparting a protective coating or film to such surfaces. This application is a continuation-in-part of our co-pending applications Serial Nos. 852,932 and 30,430, filed November 16, 1959, and May 20, 1960, respectively, both now abandoned. As used herein, the word aluminum includes pure aluminum, commercial aluminum containing the usual impurities, and aluminum base alloys.
Aluminum surfaces provided with artificial oxide coatings or films may afiord high insulating properties, and increased resistance against corrosion, chemical action and the like. Such protective oxide coatings or films may be produced commercially by chemical or electrochemical methods. For example, an oxide coating may be produced by treating the aluminum surface with an alkaline solution of a carbonate, usually a sodium carbonate-chromate solution. In another common method, an oxide coating may be produced by the anodic oxidation of the aluminum surface whereby the aluminum is made the anode is an electrolytic solution such as sulfuric acid solution or chromic acid solution. However, oxide coatings formed by these well-known commercial methods are amorphous, relatively porous and absorbent. The anodic coatings generally are sealed as by immersing the aluminum article in boiling water or a boiling nickel acetate solution. Sealing renders the oxide coating nonabsorbent thereby minimizing corrosion or staining of the coating. In order to aflord sufficient protection with such coatings, it is essential to produce a relatively thick oxide film, and sometimes anodic oxide coatings are made as thick as about one mil or more. However, relatively thick, hard coatings, being somewhat brittle, have a tendency to craze as, for example, when Wound in a small radius or bent at an acute angle, and therefore are somewhat limited in applications.
Another known method for producing an oxide film on an aluminum surface comprises treating the surface with boiling water usually for one or more hours, and often as much as three hours or even longer. Oxide films formed in this manner are hard, crystalline films of tic-alumina monohydrate, represented by the formula Al O -H O. Relatively thin conversion films of this nature exhibit high resistance to corrosion or chemical attack and high electrical insulating properties. For most applications, the thickness of the film should not be less than about 0.01 mil. However, use of a-alumina monohydrate surface films has attained only very limited commercial success because of the prolonged treatment required for forming a film of suflicient thickness.
In our co-pending United States application entitled Treating Aluminum Surfaces, Serial No. 86,867, filed concurrently herewith, we describe producing an a-alumina monohydrate film on an aluminum surface by immersing the same in an aqueous bath of certain slightly soluble alkaline earth compounds. In such process the oxide film may be formed in a relatively short period of time by maintaining the temperature of the bath at 175 F. or above. We have found, quite unexpectedly, that substantially thicker oxide coatings may be produced on an aluminum surface by immersing the same in a solution consisting essentially of water and magnesium oxide. Further, such a solution may be employed over a Wider temperature range than is referred to in our concurrently filed application. The increased thickness of the coating is attributable to the presence of hydrated magnesium oxide, often in association with some hydrated aluminum oxides. Coatings of this nature show high electrical insulating properties. The hydrated magnesium oxide is generally found present in an amount of at least about 20% by Weight of the coating, and may even comprise the major part of the coating. For suitable electrical insulating applications, the total thickness of the coating should not be less than about 0.1 mil and may be higher.
It is, therefore, the primary object of this invention to provide an improved method of imparting a protective coating or film to an aluminum surface in a relatively short period of time by employing a chemical method.
It is another object of the invention to form a coating or film comprising hydrated magnesium oxide on an aluminum surface, which coating or film is characterized by high insulating properties.
In accordance with the present invention, an oxide coating may be produced on an aluminum surface by immersing the same-in a Warm or hot solution consisting essentially of water and magnesium oxide, containing not less than about 0.5 gram per liter of magnesium oxide so that such compound is present in the solution in an amount in excess of its solubility in the solution. Solutions of less than about 0.5 gram per liter of magnesium oxide do not produce a coating of the thickness usually desired. On the other hand, generallyno substantial benefit appears to be gained by employing more than about 10 grams per liter of magnesium oxide. For best results, and for relative ease of operation, the solution preferably contains about 3 to 6 grams per liter of magnesium oxide. A dense, crystalline oxide film comprising hydrated magnesium oxide, of thickness ordinarily desired, may be so imparted to the aluminum surface by a single immersion in the solution for at least about 1 minute.
It has been found that the solution employed in accordance with our procedure for producing the coating has a pH of not less than about 8.5 and may be as high as 11, a pH above 10 being particularly desirable for carrying out the process in a short period of time. Generally, treating aluminum surfaces in a solution having a pH lower than approximately 8.5 proceeds too slowly to be economically feasible, particularly for continuous coating operations. On the other hand, since the alkalinity of the solution normally does not exceed a pH of about 11, any substantial etching action resulting in dissolving away of the aluminum metal and oxide that forms is avoided.
It is be observed that because magnesium oxide is only slightly soluble in water, even at elevated temperatures, the relatively low concentration of the compound in solution renders the aqueous solution alkaline within the pH range found desirable for the practice of our invention, thereby obviating the need for a buffer. Magnesium oxide has a maximum solubility of about 0.09 gram per liter in hot water. A solution of magnesium oxide has a pH of about 9.5 or higher, at 150 R, which may be readily maintained by the desired excess of undissolved magnesium oxide. Thus, employing only a single compound n low concentrations results in substantial economic savings.
According to our invention, the desired oxide coating can but be obtained #by treating the aluminum surface in a bath as herein described, which is maintained at a temperature above about -F., and preferably between about F. and 200 F. Employing bath temperatu-res lower than about 125 F. extends considerably the time required for producing the oxide coating (or producies undesirably thin films) and, therefore, is not practica Immersing an aluminum article in the aqueous solution of magnesium oxide for about 1 to 15 minutes, and preferably 3 to 12 minutes, will produce the desired crystalline oxide film, when operating within the above-described temperature ranges. More prolonged immersions may increaseslightly the thickness of oxide coating produced, but this increase generally is not suificient to warrant the longer irnmersions. On the other hand, immersions for less than about 1 minute may in some cases be useful, but generally are not sufiicient to produce an oxide surface coating of depth usually desired.
Aluminum panels treated in accordance with our invention were tested for the DC. voltage breakdown of the oxide coating to determine the insulating properties of the coating. The voltage breakdown tester was that developed by the National Bureau of Standards and published in The Review of Scientific Instruments, vol. 24, No. 6, p. 458 (June 1953), employing a one ounce copper probe. The coatings of hydrated magnesium oxide formed on the treated panels had thicknesses between about 0.11 to 0.16 mil. The results are set forth in the Aluminum panels having a natural oxide film exhibit an average voltage breakdown of less than 10.
The hydrated magnesium oxide coating formed on an aluminum surface in accordance with our invention is characterized by high insulating properties. Aluminum strip provided with this film is useful, for example, in electrical condensers or foil Wound coils where windings of small radii would not craze the thin oxide film.
Having described our invention, we claim:
1. The method of producing an oxide coating on an aluminum surface, comprising immersing an aluminum surface, for at least about 1 minute, in a solution maintained at a temperature above about 125 and consisting essentially of water and at least about 0.5 gram per liter of magnesium oxide, said magnesium oxide rendering the solution alkaline within a pH range of approximately 8.5 to 11, whereby a crystalline coating comprising hydrated magnesium oxide is formed on the aluminum surface.
2. The method of claim 1 wherein the solution contains about 3 to 10 grams per liter of magnesium oxide.
3. The method of claim 1 wherein the solution is maintained at a temperature between about 140 F. and 200 F.
4. The method of claim 1 wherein the aluminum surface is immersed for about 1 to 15 minutes.
References Cited in the file of this patent UNITED STATES PATENTS 1,846,844 Clark Feb. 23, 1932 2,129,840 Hessenbruch Sept. 13, 1938 2,250,472 -De Long July 29, 1941 2,859,148 Altenpohl Nov. 4, 1958
Claims (1)
1. THE METHOD OF PRODUCING AN OXIDE COARTING ALUMINUM SURFACE, COMPRISING IMMERSING AN ALUMINUM SURFACE, FOR AT LEAST ABOUT 1 MINUTE, IN A SOLUTION MAINTAINED AT A TEMPERATURE ABOVE ABOUT 152*F. AND CONSISTING ESSENTIALLY OF WATER AND AT LEAST ABOUT 0.5 GRAM PER LITER OF MAGNESIUM OXIDE, SAID MAGNESIUM OXIDE RENDERING THE SOLUTION ALKALINE WITHIN A PH RANGE OF APPROXIMATELY 8.5 TO 11, WHEREBY A CRYSTALLINE COATING COMPRISING HYDRATED MAGNESIUM OXIDE IS FORMED ON THE ALUMINUM SURFACE.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US86866A US3039898A (en) | 1961-02-03 | 1961-02-03 | Coating aluminum surfaces |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US86866A US3039898A (en) | 1961-02-03 | 1961-02-03 | Coating aluminum surfaces |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3039898A true US3039898A (en) | 1962-06-19 |
Family
ID=22201402
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US86866A Expired - Lifetime US3039898A (en) | 1961-02-03 | 1961-02-03 | Coating aluminum surfaces |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US3039898A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3247026A (en) * | 1962-02-20 | 1966-04-19 | Continental Can Co | Process of producing an oxide coating on magnesium-aluminum alloys |
| US3622390A (en) * | 1969-02-18 | 1971-11-23 | Du Pont | Process for improving capacitors |
| US3866311A (en) * | 1971-06-14 | 1975-02-18 | Nat Semiconductor Corp | Method of providing electrically isolated overlapping metallic conductors |
| US4463219A (en) * | 1980-05-16 | 1984-07-31 | Sumitomo Electric Industries, Ltd. | Compound cable |
| US4555294A (en) * | 1984-04-03 | 1985-11-26 | Imperial Clevite Inc. | Inorganic composition adapted for use in bonding a high temperature resistant polymeric material to an aluminum base substrate |
| US4586977A (en) * | 1984-04-03 | 1986-05-06 | Imperial Clevite Inc. | Method of bonding a high temperature resistant polymeric material to an aluminum base substrate |
| US4648910A (en) * | 1984-04-03 | 1987-03-10 | Clevite Industries Inc. | Method of bonding a high temperature resistant polymeric material to an aluminum base substrate and article therefrom |
| US4759805A (en) * | 1980-03-24 | 1988-07-26 | Fujikura Cable Works Ltd. | Aluminum conductor of low audible noise transmission |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1846844A (en) * | 1929-07-16 | 1932-02-23 | Gen Electric | Process of treating aluminum |
| US2129840A (en) * | 1935-09-24 | 1938-09-13 | Hessenbruch Werner | Heat-resisting object containing iron and aluminum |
| US2250472A (en) * | 1938-08-12 | 1941-07-29 | Dow Chemical Co | Method of producing colored coatings upon magnesium and its alloys |
| US2859148A (en) * | 1954-12-16 | 1958-11-04 | Aluminium Walzwerke Singen | Method of producing a bohmite layer on etched aluminum foils |
-
1961
- 1961-02-03 US US86866A patent/US3039898A/en not_active Expired - Lifetime
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1846844A (en) * | 1929-07-16 | 1932-02-23 | Gen Electric | Process of treating aluminum |
| US2129840A (en) * | 1935-09-24 | 1938-09-13 | Hessenbruch Werner | Heat-resisting object containing iron and aluminum |
| US2250472A (en) * | 1938-08-12 | 1941-07-29 | Dow Chemical Co | Method of producing colored coatings upon magnesium and its alloys |
| US2859148A (en) * | 1954-12-16 | 1958-11-04 | Aluminium Walzwerke Singen | Method of producing a bohmite layer on etched aluminum foils |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3247026A (en) * | 1962-02-20 | 1966-04-19 | Continental Can Co | Process of producing an oxide coating on magnesium-aluminum alloys |
| US3622390A (en) * | 1969-02-18 | 1971-11-23 | Du Pont | Process for improving capacitors |
| US3866311A (en) * | 1971-06-14 | 1975-02-18 | Nat Semiconductor Corp | Method of providing electrically isolated overlapping metallic conductors |
| US4759805A (en) * | 1980-03-24 | 1988-07-26 | Fujikura Cable Works Ltd. | Aluminum conductor of low audible noise transmission |
| US4463219A (en) * | 1980-05-16 | 1984-07-31 | Sumitomo Electric Industries, Ltd. | Compound cable |
| US4966635A (en) * | 1980-05-16 | 1990-10-30 | Sumitomo Electric Industries, Ltd. | Method of making a compound cable |
| US4555294A (en) * | 1984-04-03 | 1985-11-26 | Imperial Clevite Inc. | Inorganic composition adapted for use in bonding a high temperature resistant polymeric material to an aluminum base substrate |
| US4586977A (en) * | 1984-04-03 | 1986-05-06 | Imperial Clevite Inc. | Method of bonding a high temperature resistant polymeric material to an aluminum base substrate |
| US4648910A (en) * | 1984-04-03 | 1987-03-10 | Clevite Industries Inc. | Method of bonding a high temperature resistant polymeric material to an aluminum base substrate and article therefrom |
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