US2993819A - Process for treating aluminum surfaces - Google Patents
Process for treating aluminum surfaces Download PDFInfo
- Publication number
- US2993819A US2993819A US21777A US2177760A US2993819A US 2993819 A US2993819 A US 2993819A US 21777 A US21777 A US 21777A US 2177760 A US2177760 A US 2177760A US 2993819 A US2993819 A US 2993819A
- Authority
- US
- United States
- Prior art keywords
- aluminum
- fluoride
- coating
- temperature
- sodium
- 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.)
- Expired - Lifetime
Links
- 229910052782 aluminium Inorganic materials 0.000 title claims description 24
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 title claims description 24
- 238000000034 method Methods 0.000 title claims description 16
- 238000000576 coating method Methods 0.000 claims description 32
- PUZPDOWCWNUUKD-UHFFFAOYSA-M sodium fluoride Chemical compound [F-].[Na+] PUZPDOWCWNUUKD-UHFFFAOYSA-M 0.000 claims description 24
- 239000011248 coating agent Substances 0.000 claims description 23
- 239000011775 sodium fluoride Substances 0.000 claims description 12
- 235000013024 sodium fluoride Nutrition 0.000 claims description 12
- -1 SODIUM ALUMINUM FLUORIDE Chemical compound 0.000 claims description 10
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 claims description 9
- 229910000040 hydrogen fluoride Inorganic materials 0.000 claims description 9
- IRPGOXJVTQTAAN-UHFFFAOYSA-N 2,2,3,3,3-pentafluoropropanal Chemical compound FC(F)(F)C(F)(F)C=O IRPGOXJVTQTAAN-UHFFFAOYSA-N 0.000 claims description 7
- KLZUFWVZNOTSEM-UHFFFAOYSA-K Aluminum fluoride Inorganic materials F[Al](F)F KLZUFWVZNOTSEM-UHFFFAOYSA-K 0.000 claims description 7
- 229910052751 metal Inorganic materials 0.000 claims description 4
- 239000002184 metal Substances 0.000 claims description 4
- 230000007797 corrosion Effects 0.000 description 10
- 238000005260 corrosion Methods 0.000 description 10
- 239000007789 gas Substances 0.000 description 10
- 229910000831 Steel Inorganic materials 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 8
- 239000010959 steel Substances 0.000 description 8
- 239000000758 substrate Substances 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 5
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 239000001257 hydrogen Substances 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 239000004411 aluminium Substances 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 238000000151 deposition Methods 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 238000001771 vacuum deposition Methods 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 1
- 230000001464 adherent effect Effects 0.000 description 1
- 238000005269 aluminizing Methods 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000009877 rendering Methods 0.000 description 1
- 238000005201 scrubbing Methods 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 238000007738 vacuum evaporation Methods 0.000 description 1
Images
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
- C23C26/00—Coating not provided for in groups C23C2/00 - C23C24/00
Definitions
- This invention relates to coating and more particularly to the treatment of metallic coatings.
- a principal object of the present invention is to provide a process for improving the corrosion resistance of metallic coatings, particularly of aluminum.
- Another object of the invention is to provide a process for improving the corrosion resistance of metallic coatings obtained by vacuum evaporating and depositing a metal upon a substrate or article.
- Still another object of the invention is to provide a process for improving the corrosion resistance of vacuum-deposited aluminum coatings.
- Still another object of the invention is to provide a process for improving the corrosion resistance of aluminum which has been vacuum-deposited upon steel strip.
- the invention accordingly comprises the process involving the several steps and the relation and order of one or more of such steps with respect to each of the others which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.
- the process of the present invention for rendering aluminum coatings more corrosion resistant and for imparting longer effectiveness thereto comprises subjecting an aluminum-coated metal substrate or article to hydrogen fluoride gas at an elevated temperature of between about 200 and 400 C., then passing the coated substrate through an aqueous sodium fluoride bath maintained at a temperature between about 80 and 90 C., and baking the resultant sodium aluminum fluoride coating.
- the baked sodium aluminum fluoride coating is rinsed with water to remove any sodium fluoride which may be present and then dried.
- reaction chamber 10 into which there is introduced through conduit 12 hydrogen fluoride gas from a suitable source.
- the chamber 10 is provided with suitable heating means 14 such as, for example, resistance heating and the like.
- suitable heating means 14 such as, for example, resistance heating and the like.
- the reaction chamber 10 is preferably heated to a temperature between about 200 and 400 C.
- Hydrogen fluoride gas and hydrogen which results from the reaction are removed from 2 chamber 10 through conduit 16 and suitably disposed such as by scrubbing with a liquid in which the gases possess substantial solubility.
- Roller seals 18 are provided at each end of the chamber '10. The pressure within the chamber is maintained at atmospheric or somewhat above atmospheric pressure during operation.
- Substrate 20 is guided by rollers 22 through a concentrated aqueous sodium fluoride bath 24 contained within vessel 26 preferably heated to a temperature between about to C. by suitable heating means 28, e.g., resistance heating means.
- suitable heating means 28 e.g., resistance heating means.
- the resultant coating comprising sodium aluminum fluoride is baked by heating means 30 here shown as being heat lamps.
- the baked coating is preferably rinsed with water and then dried.
- a metallic substrate or sheet material such as steel strip having at least one side coated with aluminum is introduced into reaction chamber '10.
- the aluminum coating is produced by vacuum evaporation and deposition. It is obvious that aluminumcoated steel strip may be fed directly from a vacuum coating system into the reaction chamber 10 so as to provide for one continuous process of vacuum aluminizing and treatment of the aluminum coating to improve the corrosion resistance thereof.
- the aluminum-coated steel strip while passing through chamber 10 is subjected to elevated temperatures preferably on the order of between about 200 and 400 C. and to suflicient hydrogen fluoride gas.
- the aluminum or at least the surface portions of the aluminum coating react with the hydrogen fluonide to produce aluminum fluoride and hydrogen. This reaction is as follows:
- the pressure within the chamber 10 is maintained at atmospheric or slightly above. Some hydrogen gas leaks out through the seals and some is removed from the chamber 10 with hydrogen fluoride gas via conduit 16 and suitably disposed of or the gases separated and recovered.
- the steel strip having thereon a coating comprising aluminum fluoride is cooled such as by running through an air gap prior to being immersed in a concentrated aqueous solution of sodium fluoride preferably maintained at a temperature between about 80 and 90 C.
- aqueous sodium fluoride bat-h results in the conversion of this aluminum fluoride coating to sodium aluminum fluoride. This reaction is as follows:
- the resultant sodium aluminum fluoride coating is then baked, for example, at a temperature on the order of about 200 C. To remove any sodium fluoride that may have adhered to the coating, it may be rinsed with water and then dried.
- a process for treating an aluminum coated metal article surface which comprises subjecting the aluminum coating of said article to hydrogen fluoride gas at a temperature between about 200 and 400 C., contacting the resultant aluminum fluoride surface with a solution of sodium fluoride maintained at a temperature between about 80 and 90 C., and then baking the resultant sodium aluminum fluoride coating at a temperature of about 200 C.
- a process for treating aluminum-coated steel strip which comprises passing said strip through an atmosphere comprising hydrogen fluoride gas maintained at a temperature between about 200 and 400 C. for a period of time suflicient to convert the surface of said coating to aluminum fluoride, then passing said strip through a solution comprising sodium fluoride maintained at a temperature between about 80 and 90 C., and thereafter sistance to vacuum-alumiuized steel strip which comprises subjecting the vacuum-deposited aluminum coating to an atmosphere comprising hydrogen fluoride gas heated to a temperature between about 200 and 400 C., contacting the resultant coating comprising aluminum fluoride with a concentrated aqueous solution of sodium fluoride heated to a temperature between about and C., and thereafter baking the resultant coating comprising sodium aluminum fluoride at a temperature of about 200 C.
Description
July 25, 1961 G. NESSIM 2,993,819
PROCESS FOR TREATING ALUMINIUM SURFACES Filed April 12, 1960 INVENTOR.
'BY W5:
r* 2,993,819 1C6 Patented July 25, 1961 2,993,819 PROCESS FOR TREATING ALUMINIUM SURFACES Leon Gabriel Nessim, Geneva, Switzerland, assignor to 'tChimel S.A., Geneva, Switzerland, a Swiss corpora- Filed Apr. 12, 1960, Ser. No. 21,777 5 Claims. (Cl. 1486.27)
This invention relates to coating and more particularly to the treatment of metallic coatings.
A principal object of the present invention is to provide a process for improving the corrosion resistance of metallic coatings, particularly of aluminum.
Another object of the invention is to provide a process for improving the corrosion resistance of metallic coatings obtained by vacuum evaporating and depositing a metal upon a substrate or article.
Still another object of the invention is to provide a process for improving the corrosion resistance of vacuum-deposited aluminum coatings.
Still another object of the invention is to provide a process for improving the corrosion resistance of aluminum which has been vacuum-deposited upon steel strip.
Other objects of the invention will in part be obvious and will in part appear hereinafter.
The invention accordingly comprises the process involving the several steps and the relation and order of one or more of such steps with respect to each of the others which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.
For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing which is a diagrammatic, schematic view of one embodiment of the invention.
It is well known that many metallic substrates or articles which are subject to corrosive oxidation or deterioration by saline conditions or the like may be coated with aluminum to provide corrosion resistance thereto. Thin aluminum coatings are usually of a porous nature and thus usually do not provide adequate corrosion-resistant coatings. Relatively thick aluminum coatings, i.e., in excess of about 1 micron, generally provide a somewhat more durable corrosion-resistant coating. The present invention is particularly directed to improving the corrosion resistance of aluminum coatings such as those produced by vacuum-depositing processes.
The process of the present invention for rendering aluminum coatings more corrosion resistant and for imparting longer effectiveness thereto comprises subjecting an aluminum-coated metal substrate or article to hydrogen fluoride gas at an elevated temperature of between about 200 and 400 C., then passing the coated substrate through an aqueous sodium fluoride bath maintained at a temperature between about 80 and 90 C., and baking the resultant sodium aluminum fluoride coating. In one embodiment of the invent-ion the baked sodium aluminum fluoride coating is rinsed with water to remove any sodium fluoride which may be present and then dried.
Referring now to the drawing, there is shown one prefer-red embodiment of the invention wherein represents a reaction chamber into which there is introduced through conduit 12 hydrogen fluoride gas from a suitable source. The chamber 10 is provided with suitable heating means 14 such as, for example, resistance heating and the like. During operation the reaction chamber 10 is preferably heated to a temperature between about 200 and 400 C. Hydrogen fluoride gas and hydrogen which results from the reaction are removed from 2 chamber 10 through conduit 16 and suitably disposed such as by scrubbing with a liquid in which the gases possess substantial solubility. Roller seals 18 are provided at each end of the chamber '10. The pressure within the chamber is maintained at atmospheric or somewhat above atmospheric pressure during operation.
In carrying out the preferred process of the .present invention, a metallic substrate or sheet material such as steel strip having at least one side coated with aluminum is introduced into reaction chamber '10. In one embodiment, the aluminum coating is produced by vacuum evaporation and deposition. It is obvious that aluminumcoated steel strip may be fed directly from a vacuum coating system into the reaction chamber 10 so as to provide for one continuous process of vacuum aluminizing and treatment of the aluminum coating to improve the corrosion resistance thereof. The aluminum-coated steel strip while passing through chamber 10 is subjected to elevated temperatures preferably on the order of between about 200 and 400 C. and to suflicient hydrogen fluoride gas. The aluminum or at least the surface portions of the aluminum coating react with the hydrogen fluonide to produce aluminum fluoride and hydrogen. This reaction is as follows:
The pressure within the chamber 10 is maintained at atmospheric or slightly above. Some hydrogen gas leaks out through the seals and some is removed from the chamber 10 with hydrogen fluoride gas via conduit 16 and suitably disposed of or the gases separated and recovered.
Upon removal from chamber 10, the steel strip having thereon a coating comprising aluminum fluoride is cooled such as by running through an air gap prior to being immersed in a concentrated aqueous solution of sodium fluoride preferably maintained at a temperature between about 80 and 90 C. Contact with the aqueous sodium fluoride bat-h results in the conversion of this aluminum fluoride coating to sodium aluminum fluoride. This reaction is as follows:
The resultant sodium aluminum fluoride coating is then baked, for example, at a temperature on the order of about 200 C. To remove any sodium fluoride that may have adhered to the coating, it may be rinsed with water and then dried.
There is thus produced, according to the present invention, a steel strip having a hard flexible, adherent sodium aluminum fluoride coating which is extremely resistant to even the most severe corrosive forces for long periods of time.
Since certain changes may be made in the above process without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.
What I claim is:
1. A process for treating an aluminum coated metal article surface which comprises subjecting the aluminum coating of said article to hydrogen fluoride gas at a temperature between about 200 and 400 C., contacting the resultant aluminum fluoride surface with a solution of sodium fluoride maintained at a temperature between about 80 and 90 C., and then baking the resultant sodium aluminum fluoride coating at a temperature of about 200 C.
2. A process for treating aluminum-coated steel strip which comprises passing said strip through an atmosphere comprising hydrogen fluoride gas maintained at a temperature between about 200 and 400 C. for a period of time suflicient to convert the surface of said coating to aluminum fluoride, then passing said strip through a solution comprising sodium fluoride maintained at a temperature between about 80 and 90 C., and thereafter sistance to vacuum-alumiuized steel strip which comprises subjecting the vacuum-deposited aluminum coating to an atmosphere comprising hydrogen fluoride gas heated to a temperature between about 200 and 400 C., contacting the resultant coating comprising aluminum fluoride with a concentrated aqueous solution of sodium fluoride heated to a temperature between about and C., and thereafter baking the resultant coating comprising sodium aluminum fluoride at a temperature of about 200 C.
5. A process according to claim 4, wherein the baked coating comprising sodium aluminum fluoride is rinsed with water and then dried.
References Cited in the file of this patent UNITED STATES PATENTS 2,092,033 Stroup Sept. 7, 1937 2,092,034 Stroup Sept. 7, 1937 2,382,432 McManus et al. Aug. 14, 1945 2,824,819 Smith Feb. 25, 1958 ,885,316 Milliken May 5, 1959
Claims (1)
1. A PROCESS FOR TREATING AN ALUMINUM COATED METAL ARTICLE SURFACE WHICH COMPRISES SUBJECTING THE ALUMINUM COATING OF SAID ARTICLE TO HYDROGEN FLUORIDE GAS AT A TEMPERATURE BETWEEN ABOUT 200* AND 400*C., CONTACTING THE RESULTANT ALUMINUM FLUORIDE SURFACE WITH A SOLUTION OF SODIUM FLUORIDE MAINTAINED AT A TEMPERATURE BETWEEN ABOUT 80* AND 90*C., AND THEN BAKING THE RESULTANT SODIUM ALUMINUM FLUORIDE COATING AT A TEMPERATURE OF ABOUT 200*C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US21777A US2993819A (en) | 1960-04-12 | 1960-04-12 | Process for treating aluminum surfaces |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US21777A US2993819A (en) | 1960-04-12 | 1960-04-12 | Process for treating aluminum surfaces |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2993819A true US2993819A (en) | 1961-07-25 |
Family
ID=21806093
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US21777A Expired - Lifetime US2993819A (en) | 1960-04-12 | 1960-04-12 | Process for treating aluminum surfaces |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2993819A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3169892A (en) * | 1959-04-08 | 1965-02-16 | Jerome H Lemelson | Method of making a multi-layer electrical circuit |
| US3529987A (en) * | 1956-05-28 | 1970-09-22 | Jerome H Lemelson | Method of coating conduit |
| US4105473A (en) * | 1977-09-14 | 1978-08-08 | Ford Motor Company | Method of protecting an aluminum braking surface |
| US4126458A (en) * | 1977-08-11 | 1978-11-21 | Xerox Corporation | Inorganic fluoride reversal carrier coatings |
| US5069938A (en) * | 1990-06-07 | 1991-12-03 | Applied Materials, Inc. | Method of forming a corrosion-resistant protective coating on aluminum substrate |
| US5192610A (en) * | 1990-06-07 | 1993-03-09 | Applied Materials, Inc. | Corrosion-resistant protective coating on aluminum substrate and method of forming same |
| US6280597B1 (en) * | 1997-09-12 | 2001-08-28 | Showa Denko K.K. | Fluorinated metal having a fluorinated layer and process for its production |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2092034A (en) * | 1936-10-01 | 1937-09-07 | Aluminum Co Of America | Thermal treatment of aluminous metals |
| US2092033A (en) * | 1936-10-01 | 1937-09-07 | Aluminum Co Of America | Heat treatment of aluminous metals |
| US2382432A (en) * | 1940-08-02 | 1945-08-14 | Crown Cork & Seal Co | Method and apparatus for depositing vaporized metal coatings |
| US2824819A (en) * | 1956-05-11 | 1958-02-25 | Millard F Smith | Method for oxide insulating aluminum conductors |
| US2885316A (en) * | 1958-07-21 | 1959-05-05 | Aluminum Co Of America | Method for degassing aluminum articles by means of a vaporous fluoride |
-
1960
- 1960-04-12 US US21777A patent/US2993819A/en not_active Expired - Lifetime
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2092034A (en) * | 1936-10-01 | 1937-09-07 | Aluminum Co Of America | Thermal treatment of aluminous metals |
| US2092033A (en) * | 1936-10-01 | 1937-09-07 | Aluminum Co Of America | Heat treatment of aluminous metals |
| US2382432A (en) * | 1940-08-02 | 1945-08-14 | Crown Cork & Seal Co | Method and apparatus for depositing vaporized metal coatings |
| US2824819A (en) * | 1956-05-11 | 1958-02-25 | Millard F Smith | Method for oxide insulating aluminum conductors |
| US2885316A (en) * | 1958-07-21 | 1959-05-05 | Aluminum Co Of America | Method for degassing aluminum articles by means of a vaporous fluoride |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3529987A (en) * | 1956-05-28 | 1970-09-22 | Jerome H Lemelson | Method of coating conduit |
| US3169892A (en) * | 1959-04-08 | 1965-02-16 | Jerome H Lemelson | Method of making a multi-layer electrical circuit |
| US4126458A (en) * | 1977-08-11 | 1978-11-21 | Xerox Corporation | Inorganic fluoride reversal carrier coatings |
| US4105473A (en) * | 1977-09-14 | 1978-08-08 | Ford Motor Company | Method of protecting an aluminum braking surface |
| US5069938A (en) * | 1990-06-07 | 1991-12-03 | Applied Materials, Inc. | Method of forming a corrosion-resistant protective coating on aluminum substrate |
| US5192610A (en) * | 1990-06-07 | 1993-03-09 | Applied Materials, Inc. | Corrosion-resistant protective coating on aluminum substrate and method of forming same |
| US6280597B1 (en) * | 1997-09-12 | 2001-08-28 | Showa Denko K.K. | Fluorinated metal having a fluorinated layer and process for its production |
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