US2248063A - Method of treating electrolytic coatings on magnesium and its alloys - Google Patents
Method of treating electrolytic coatings on magnesium and its alloys Download PDFInfo
- Publication number
- US2248063A US2248063A US204388A US20438838A US2248063A US 2248063 A US2248063 A US 2248063A US 204388 A US204388 A US 204388A US 20438838 A US20438838 A US 20438838A US 2248063 A US2248063 A US 2248063A
- Authority
- US
- United States
- Prior art keywords
- magnesium
- alloys
- solution
- coatings
- coating
- 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
- 238000000576 coating method Methods 0.000 title description 21
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 title description 17
- 239000011777 magnesium Substances 0.000 title description 17
- 229910052749 magnesium Inorganic materials 0.000 title description 17
- 238000000034 method Methods 0.000 title description 8
- 229910045601 alloy Inorganic materials 0.000 title description 6
- 239000000956 alloy Substances 0.000 title description 6
- 239000000243 solution Substances 0.000 description 18
- 239000011248 coating agent Substances 0.000 description 13
- 238000011282 treatment Methods 0.000 description 9
- SOCTUWSJJQCPFX-UHFFFAOYSA-N dichromate(2-) Chemical compound [O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O SOCTUWSJJQCPFX-UHFFFAOYSA-N 0.000 description 8
- 230000007797 corrosion Effects 0.000 description 7
- 238000005260 corrosion Methods 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- 150000003839 salts Chemical class 0.000 description 6
- 238000007789 sealing Methods 0.000 description 6
- 229910021538 borax Inorganic materials 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 5
- 235000010339 sodium tetraborate Nutrition 0.000 description 5
- BSVBQGMMJUBVOD-UHFFFAOYSA-N trisodium borate Chemical compound [Na+].[Na+].[Na+].[O-]B([O-])[O-] BSVBQGMMJUBVOD-UHFFFAOYSA-N 0.000 description 5
- BTBUEUYNUDRHOZ-UHFFFAOYSA-N Borate Chemical compound [O-]B([O-])[O-] BTBUEUYNUDRHOZ-UHFFFAOYSA-N 0.000 description 4
- 229910019142 PO4 Inorganic materials 0.000 description 4
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 4
- 239000007864 aqueous solution Substances 0.000 description 4
- ZCDOYSPFYFSLEW-UHFFFAOYSA-N chromate(2-) Chemical compound [O-][Cr]([O-])(=O)=O ZCDOYSPFYFSLEW-UHFFFAOYSA-N 0.000 description 4
- 235000021317 phosphate Nutrition 0.000 description 4
- 229910000861 Mg alloy Inorganic materials 0.000 description 3
- 238000009835 boiling Methods 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 3
- 239000010452 phosphate Substances 0.000 description 3
- 229910021653 sulphate ion Inorganic materials 0.000 description 3
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 2
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 239000011572 manganese Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- JHWIEAWILPSRMU-UHFFFAOYSA-N 2-methyl-3-pyrimidin-4-ylpropanoic acid Chemical compound OC(=O)C(C)CC1=CC=NC=N1 JHWIEAWILPSRMU-UHFFFAOYSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- JOSWYUNQBRPBDN-UHFFFAOYSA-P ammonium dichromate Chemical compound [NH4+].[NH4+].[O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O JOSWYUNQBRPBDN-UHFFFAOYSA-P 0.000 description 1
- 238000007743 anodising Methods 0.000 description 1
- 150000001844 chromium Chemical class 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- GRWVQDDAKZFPFI-UHFFFAOYSA-H chromium(III) sulfate Chemical compound [Cr+3].[Cr+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O GRWVQDDAKZFPFI-UHFFFAOYSA-H 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 150000003013 phosphoric acid derivatives Chemical class 0.000 description 1
- 159000000001 potassium salts Chemical class 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
- C25D11/02—Anodisation
- C25D11/30—Anodisation of magnesium or alloys based thereon
Definitions
- This invention relates to the treatment of electrolytically formed coatings on magnesium and its alloys and one of its objects is to increase the durability and the protective characteristics of the film by sealing the coating.
- the method specifically relates to the treating of electrolytic coatings on magnesium and its alloys with a solution in the presence of heat so "as to form a seal that not only increases the. durability of the article coated to wear but also improves its resistance to corrosion.
- the article to be treated in this manner which has been coated electrolytically, is washed free of solution, providing the electrolytic bath is basically difierent from the solution used in my sealing method and is then immersed in a hot solution of sealing compoundsppreferably at or change in color, whereas the unsealed coating above the boiling point of the solution, but below the fusion point of the metal.
- the sealing solution should contain a corrosion inhibiting ion such as either a chromate or dichromate and a second salt as a reacting ion such as manganese -or chromium or borate, phosphate, fluoride or a combination of any of the said second salts.
- concentration of the salts is limited only by their solubility, but may be varied to conform with timeof "application and quality of seal. Good seals of coated metal have been obtained by subjecting the coatings to treatment-for period-s varyingfrom five minutes to one hour.
- anodic coating be formed on magnesium or its alloys in a bath of 10 per cent dichromate and a 2 per cent monoba-sic phosphate and the coating has been washed free of anodizing solution, its corrosion resistance will be greatly improved if it is immersed in a solution of dichromate and manganous sulphate at boiling temperature of water or above.
- the sealing solution may be variedto contain a trivalent chromium salt as chromiuin-acetate or sulphate or fluoride.
- a chromate may be introduced or substituted in the solution or a phosphate may be substituted or. added when the solution is of such composition not to cause detrimental intersolution reactions.
- compositions which will satisfactorily'seal electrolytic coatings on magnesimn, the following are cited:
- the pH of the sealing'solutions described herein may be on the acid or alkaline side, depending upon the relative proportions of the salts employed, and the characteristic pH of solutions of the individual salts.
- a method of producing corrosion-resistant magnesium or magnesium alloys comprising forming an anodic coating produced by reaction with magnesium on the metal and subjecting the coating to a non-electrolytic treatment in an aqueous solution containing 8 to 12 percent water soluble dichrom-ate and 3 to 7 percent sodium borate, and maintaining the ten'rperatureof the solution during treatment substantially equivalent to the boiling point of the solution.
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemical Treatment Of Metals (AREA)
Description
Patented July 8, 1941 METHOD OF TREATING ELECTROLYTIC COATINGS ON MAGNESIUM AND ITS ALLOYS Robert W. Buzzard, Kensington, Md.
No Drawing.
Original application June 29, i
1937, Serial No. 150,932. Divided and this application April 26, 1938, Serial No. 204,388
(Granted under the act of March 3, 1883, as
I amended April 80, 1928; 370 0. G. 757) 4 Claims.
The invention disclosed and claimed herein is a division of my copending application, Serial No. 150,932, filed June 29, 1937, now Patent No. 2,203,670 of June 11, 1940.
This invention relates to the treatment of electrolytically formed coatings on magnesium and its alloys and one of its objects is to increase the durability and the protective characteristics of the film by sealing the coating.
The method specifically relates to the treating of electrolytic coatings on magnesium and its alloys with a solution in the presence of heat so "as to form a seal that not only increases the. durability of the article coated to wear but also improves its resistance to corrosion.
The article to be treated in this manner, which has been coated electrolytically, is washed free of solution, providing the electrolytic bath is basically difierent from the solution used in my sealing method and is then immersed in a hot solution of sealing compoundsppreferably at or change in color, whereas the unsealed coating above the boiling point of the solution, but below the fusion point of the metal.
The sealing solution should contain a corrosion inhibiting ion such as either a chromate or dichromate anda second salt as a reacting ion such as manganese -or chromium or borate, phosphate, fluoride or a combination of any of the said second salts. The concentration of the salts is limited only by their solubility, but may be varied to conform with timeof "application and quality of seal. Good seals of coated metal have been obtained by subjecting the coatings to treatment-for period-s varyingfrom five minutes to one hour. i
Specifically, as an example, if an anodic coating be formed on magnesium or its alloys in a bath of 10 per cent dichromate and a 2 per cent monoba-sic phosphate and the coating has been washed free of anodizing solution, its corrosion resistance will be greatly improved if it is immersed in a solution of dichromate and manganous sulphate at boiling temperature of water or above. The sealing solution may be variedto contain a trivalent chromium salt as chromiuin-acetate or sulphate or fluoride. A chromate may be introduced or substituted in the solution or a phosphate may be substituted or. added when the solution is of such composition not to cause detrimental intersolution reactions.
It should be understood that the protection obtained bymy treatment is dependent on .the
presence of an electrolytic coating and is not a prime surface treatment.
showed a radical change'in color.
As further examples of compositions which will satisfactorily'seal electrolytic coatings on magnesimn, the following are cited:
(a) 1 to 30 percent dichromate i l to 30 percent borate (b) '10 percent sodium dichromate 5 percent sodium borate (c) 5 to 10 percent ammonium dichromate 5 to 10 percent sodium borate '5 to 10 percent manganous sulphate (d) 8 to 1 2 percent dichromate Sto 7 percent sodium borate 'A double dip may also be used such as firstimmersing the electrolytically coated article in a solution of dichromate and phosphates followed by an immersion in a. solution of manganese and chromium sulphate. Ammonium and other salts may-be substituted for the sodium and potassium salts.
The pH of the sealing'solutions described herein may be on the acid or alkaline side, depending upon the relative proportions of the salts employed, and the characteristic pH of solutions of the individual salts.
Theabove mentioned substances used in the magnesium treatments are mentioned by way of illustration and not by limitation, since the invention comprehends treatments of the character indicated broadly above'and is not to be limited except by the appended claims.
The invention described herein may be manufactured or used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
What I claim is:
1. The method of producing corrosion resistant coatings on magnesium and magnesium alloys in which magnesium predominates comprising forming on the metal an anodic coating produced by reaction with magnesium and subjecting said coating to a non-electrolytic treatment in an aqueous solution containing a water soluble borate and a water soluble compound selected from group consisting of chromate and dichromate.
2. The method of producing corrosion resistuant coatings on magnesium and magnesium alloys in which magnesium predominates comprising forming on the metal an anodic coating produced by reaction with magnesium and subjectin'g said coating to a non-electrolytic treatment in an aqueous solution containing sodium borate and a water soluble compound selected from group consisting of chroma-to and dichromata,
3. A method of producing corrosion-resistant magnesium or magnesium alloys comprising forming an anodic coating produced by reaction with magnesium on the metal and subjecting the coating to a non-electrolytic treatment in an aqueous solution containing 8 to 12 percent water soluble dichrom-ate and 3 to 7 percent sodium borate, and maintaining the ten'rperatureof the solution during treatment substantially equivalent to the boiling point of the solution.
4. The method of producing corrosion resistant coatings on magnesium or alloys thereof in which magnesium predominates comprising forming on the metal an anodic coating produced by reaction with magnesium, and subjecting sail coating to a non-electrolytic treatment in an aqueous solution containing a water soluble borate and a water soluble compound selected from the group consisting of the chromates and dichromates, the pH of such solution being on the
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US204388A US2248063A (en) | 1937-06-29 | 1938-04-26 | Method of treating electrolytic coatings on magnesium and its alloys |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US150932A US2203670A (en) | 1937-06-29 | 1937-06-29 | Method of treating electrolytic coatings on magnesium and its alloys |
| US204388A US2248063A (en) | 1937-06-29 | 1938-04-26 | Method of treating electrolytic coatings on magnesium and its alloys |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2248063A true US2248063A (en) | 1941-07-08 |
Family
ID=26848174
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US204388A Expired - Lifetime US2248063A (en) | 1937-06-29 | 1938-04-26 | Method of treating electrolytic coatings on magnesium and its alloys |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2248063A (en) |
-
1938
- 1938-04-26 US US204388A patent/US2248063A/en not_active Expired - Lifetime
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