US2134830A - Process of producing corrosion resistant coatings on magnesium and high percentage magnesium alloys - Google Patents
Process of producing corrosion resistant coatings on magnesium and high percentage magnesium alloys Download PDFInfo
- Publication number
- US2134830A US2134830A US160272A US16027237A US2134830A US 2134830 A US2134830 A US 2134830A US 160272 A US160272 A US 160272A US 16027237 A US16027237 A US 16027237A US 2134830 A US2134830 A US 2134830A
- Authority
- US
- United States
- Prior art keywords
- magnesium
- high percentage
- corrosion resistant
- resistant coatings
- producing corrosion
- 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 14
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 title description 12
- 229910000861 Mg alloy Inorganic materials 0.000 title description 12
- 229910052749 magnesium Inorganic materials 0.000 title description 12
- 239000011777 magnesium Substances 0.000 title description 12
- 238000000034 method Methods 0.000 title description 10
- 238000005260 corrosion Methods 0.000 title description 9
- 230000007797 corrosion Effects 0.000 title description 9
- 239000000243 solution Substances 0.000 description 16
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 description 12
- 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 12
- 235000001055 magnesium Nutrition 0.000 description 11
- 229940091250 magnesium supplement Drugs 0.000 description 11
- 229910052751 metal Inorganic materials 0.000 description 7
- 239000002184 metal Substances 0.000 description 7
- 239000008399 tap water Substances 0.000 description 7
- 235000020679 tap water Nutrition 0.000 description 7
- 150000002500 ions Chemical class 0.000 description 6
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 5
- 229910021653 sulphate ion Inorganic materials 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- SOCTUWSJJQCPFX-UHFFFAOYSA-N dichromate(2-) Chemical compound [O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O SOCTUWSJJQCPFX-UHFFFAOYSA-N 0.000 description 4
- 238000007654 immersion Methods 0.000 description 4
- 239000007864 aqueous solution Substances 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- -1 sulphate ions Chemical class 0.000 description 3
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 238000007792 addition Methods 0.000 description 2
- 230000001464 adherent effect Effects 0.000 description 2
- 239000010953 base metal Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229910001385 heavy metal Inorganic materials 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 239000011241 protective layer Substances 0.000 description 2
- 150000003839 salts Chemical class 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
- 229910001369 Brass Inorganic materials 0.000 description 1
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 239000010951 brass Substances 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- ZCDOYSPFYFSLEW-UHFFFAOYSA-N chromate(2-) Chemical class [O-][Cr]([O-])(=O)=O ZCDOYSPFYFSLEW-UHFFFAOYSA-N 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 230000007717 exclusion Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- GQPLMRYTRLFLPF-UHFFFAOYSA-N nitrous oxide Inorganic materials [O-][N+]#N GQPLMRYTRLFLPF-UHFFFAOYSA-N 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 229910052725 zinc Inorganic materials 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
- C23C22/06—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 aqueous acidic solutions with pH less than 6
- C23C22/24—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 aqueous acidic solutions with pH less than 6 containing hexavalent chromium compounds
Definitions
- the present invention relates to a process of producing corrosion resistant coatings on mag nesium and high percentage magnesium-alloys.
- magnesium and high percentage magnesium alloys are treated with an aqueous solution ofbetween about 0.1 and l per-cent chromic acid, with the exclusion of other saline additions, but in the presence of chlorides and/or sulphates in the quantities usual in ordinary tap water.
- chromic acid in the aforesaid proportions and dissolved in water having the usual chloride and/or sulphate content of tap water coatings are formed, and that such coatings are uniformly well adherent on the base metal.
- the content of chromic acid in the solution should not exceed about 4 grms. per litre.
- the colour shade of the coating produced on the metal surface may be varied by varying the temperature or the bath according to the invention. With a temperature of 20 C. the shade is similar to that oi brass, whereas with higher temperatures the shade becomes darker. It is of some importance, however, to note that with temperatures above normal the duration of immersion necessary for producing a uniformly adherent sound coating is reduced, being approximately four minutes for a temperature of 20 and falling oil to one and a half minutes at 100 C.- The adherence and also the soundness of the coatings are not reduced when working with higher temperatures, provided that the duration of immersion is correspondingly shortened.
Landscapes
- Chemical & Material Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemical Treatment Of Metals (AREA)
- ing And Chemical Polishing (AREA)
Description
Patented Nov. '1, 1938 UNITED STATES SISTANT COATINGS HIGH PERCENTAGE Josef Martin Michel,
signor, by mesne assi Development Corporation,
Delaware No Drawing. Application August 21, 1937, Se-
rial No. 160,272. In 1936 5 Claims.
The present invention relates to a process of producing corrosion resistant coatings on mag nesium and high percentage magnesium-alloys.
It has been suggested that a treatment of magnesium and high percentage magnesium alloys with aqueous or acid solutions containing chromic acid or chromates of the alkali metals leads to the formation of a coloured protective layer on the metal which increases its resistance to corroding influences. For the purpose of imparting definite colour shades to the metal surface, an addition of heavy metal salts to the said solutions has also been suggested. In practice, however, only dichromate solutions have been hitherto used for the aforesaid purposes since experience shows that with chromic acid solutions of ordinary concentration, particularly such as do not simultaneously contain heavy metal salts, there is practically no coating formed.
On the'other hand, the treatment of high percentage magnesium alloys with acid dichromate solutions is attended with a very heavy consumption of dichromate which in turn results in rapid alteration of the acidity and the dichromate concentration of the bath. Moreover, when using acidulated baths, a; comparatively strong attack of' the-metal surface to be treated takes place whilst, when using, as is the custom, solutions in which acidulation is brought about by nitric acid, also nitrous gases are formed.
The process according to tire present invention avoids these drawbacks while at the same time affording the possibility of forming coatings having a wide range of colour shades, and also of imparting to the base metal an improved resistance to corrosion. In accordance with the present invention magnesium and high percentage magnesium alloys are treated with an aqueous solution ofbetween about 0.1 and l per-cent chromic acid, with the exclusion of other saline additions, but in the presence of chlorides and/or sulphates in the quantities usual in ordinary tap water. It has been ascertained that only when using chromic acid in the aforesaid proportions and dissolved in water having the usual chloride and/or sulphate content of tap water, coatings are formed, and that such coatings are uniformly well adherent on the base metal. Preferably the content of chromic acid in the solution should not exceed about 4 grms. per litre.
In contradistinction to the normal type ,of dipping baths employed for magnesium and high percentage magnesium alloys and consisting of nitric acid and sodium dichromate (e. g. 500 cm Bitterfeld, Germany, as-
PATENT OFFICE ON MAGNESIUM AND MAGNESIUM ALLOYS gnments, to Magnesium a corporation of Germany September 4,
of 40% HNOs, 500 cm H20, grms. K2Cr2O1-- solution No. I) a 0.4% chromic acid solution (4 grms. CrOa per litre-solution No. 11) causes practically no attack on the metal to be treated, as may be seen from the following Table I. The practically negligible increase in weight, of the metal, when using chromic acid solution, is caused by the formation of the protective layer on the surface of the metal.
The improvement obtained by the use of baths in accordance with the present invention in respect of resistance to corrosion by water may be seen from the following Table II.
Table II Decrease in weight in grams per square metre surtaoe alter 48 hours alloy Solution I 'Solution 11 1% Zn, 6% Al, 0.5% Mn, balance Mg- 7 b i l )5 Mn, 0.3 Si alance M 4.
The saving effected in consumption of C103 by the process according to the present invention over the former treatment is best shown by the fact that per square metre of surface treated and with a duration of immersion'of 30 seconds in bath No. I (former process) 500 grms. HNO: (40%) and 3 grms. .KZCIZO'! were consumed, whereas with bath No. II and a duration of immersion of four minutes the consumption is only about 1.1 grms. CrOs.
The colour shade of the coating produced on the metal surface may be varied by varying the temperature or the bath according to the invention. With a temperature of 20 C. the shade is similar to that oi brass, whereas with higher temperatures the shade becomes darker. It is of some importance, however, to note that with temperatures above normal the duration of immersion necessary for producing a uniformly adherent sound coating is reduced, being approximately four minutes for a temperature of 20 and falling oil to one and a half minutes at 100 C.- The adherence and also the soundness of the coatings are not reduced when working with higher temperatures, provided that the duration of immersion is correspondingly shortened.
1. Process of producing corrosion resistant coatings on magnesium and high percentage magnesium alloys by a treatment with a solution of between about 0.1 and about 1 percent of chromic acid in water, and containing an ion selected from the group consisting oi chloride and sulphate ions in an amount approximately equal to the content 01 such ion in ordinary tap water.
2. Process of producing corrosion resistant coatings on magnesium and high percentage magnesium alloys by a treatment with a solution of 0.4 percent of chromicacid in water, and containing. an ion selected from the group consisting of chloride and sulphate ions in an amount approximately equal to the content 01' such ion in ordinary tap water.
3. Process of producing corrosion resistant coatings on magnesium. and high percentage magnesium alloys by a treatment at elevated temperatures with a solution or between about 0.1 and'about 1 percent of chromic acid in water, and containing an ion selected from the group consisting of chloride and sulphate ions in an amount approximately equal to the content of such ion in ordinary tap water.
4. Process of producing corrosion resistant coatings on magnesium and high percentage magnesium alloys by treatment with an aqueous solution. containing between about 0.1 and about 1 per cent 01' chromic acid and having a chloride ion content approximately equal to that of. ordinary tap water. I
5. Process of producing corrosion resistant coatings on magnesium and high percentage magnesium alloys by treatment with an aqueous solution containing between about 0.1 and about 1 per cent of ,chromic acid and having'a sulphate ion content approximately equal to that oi ordinary tap water.
' JOBEF MARTIN MICHEL.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2134830X | 1936-09-04 | ||
| DE826224X | 1936-09-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2134830A true US2134830A (en) | 1938-11-01 |
Family
ID=61187889
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US160272A Expired - Lifetime US2134830A (en) | 1936-09-04 | 1937-08-21 | Process of producing corrosion resistant coatings on magnesium and high percentage magnesium alloys |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US2134830A (en) |
| BE (1) | BE421448A (en) |
| FR (1) | FR826224A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2454799A (en) * | 1944-12-09 | 1948-11-30 | Hart David | Method of producing protective coatings on magnesium powder |
| US2799601A (en) * | 1955-04-22 | 1957-07-16 | Allied Res Products Inc | Composition and method for coating zinc and zinc alloy sheets |
| US5219617A (en) * | 1989-09-19 | 1993-06-15 | Michigan Chrome And Chemical Company | Corrosion resistant coated articles and process for making same |
-
1937
- 1937-05-07 BE BE421448D patent/BE421448A/en unknown
- 1937-08-21 US US160272A patent/US2134830A/en not_active Expired - Lifetime
- 1937-09-03 FR FR826224D patent/FR826224A/en not_active Expired
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2454799A (en) * | 1944-12-09 | 1948-11-30 | Hart David | Method of producing protective coatings on magnesium powder |
| US2799601A (en) * | 1955-04-22 | 1957-07-16 | Allied Res Products Inc | Composition and method for coating zinc and zinc alloy sheets |
| US5219617A (en) * | 1989-09-19 | 1993-06-15 | Michigan Chrome And Chemical Company | Corrosion resistant coated articles and process for making same |
| US5492766A (en) * | 1989-09-19 | 1996-02-20 | Michigan Chrome And Chemical Company | Corrosion resistant coated articles and process for making same |
Also Published As
| Publication number | Publication date |
|---|---|
| FR826224A (en) | 1938-03-25 |
| BE421448A (en) | 1937-06-30 |
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