US3301719A - Chemical conversion coating for magnesium - Google Patents
Chemical conversion coating for magnesium Download PDFInfo
- Publication number
- US3301719A US3301719A US230669A US23066962A US3301719A US 3301719 A US3301719 A US 3301719A US 230669 A US230669 A US 230669A US 23066962 A US23066962 A US 23066962A US 3301719 A US3301719 A US 3301719A
- Authority
- US
- United States
- Prior art keywords
- magnesium
- coating
- solution
- chemical conversion
- conversion 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
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 title claims description 30
- 239000011777 magnesium Substances 0.000 title claims description 30
- 229910052749 magnesium Inorganic materials 0.000 title claims description 30
- 239000000126 substance Substances 0.000 title description 14
- 238000007739 conversion coating Methods 0.000 title description 13
- 238000000576 coating method Methods 0.000 claims description 26
- 229910000861 Mg alloy Inorganic materials 0.000 claims description 12
- 238000004140 cleaning Methods 0.000 claims description 6
- 238000005238 degreasing Methods 0.000 claims description 3
- 238000005554 pickling Methods 0.000 claims description 3
- 238000002360 preparation method Methods 0.000 claims description 3
- 239000000243 solution Substances 0.000 description 24
- 239000000463 material Substances 0.000 description 18
- 239000011248 coating agent Substances 0.000 description 16
- 238000007654 immersion Methods 0.000 description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 8
- 238000000034 method Methods 0.000 description 7
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 6
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 description 6
- 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 6
- VWDWKYIASSYTQR-UHFFFAOYSA-N sodium nitrate Chemical compound [Na+].[O-][N+]([O-])=O VWDWKYIASSYTQR-UHFFFAOYSA-N 0.000 description 6
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 4
- HFTNNOZFRQLFQB-UHFFFAOYSA-N ethenoxy(trimethyl)silane Chemical compound C[Si](C)(C)OC=C HFTNNOZFRQLFQB-UHFFFAOYSA-N 0.000 description 4
- 229910052938 sodium sulfate Inorganic materials 0.000 description 4
- 235000011152 sodium sulphate Nutrition 0.000 description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- -1 magnesium dichromate compound Chemical class 0.000 description 3
- 239000011780 sodium chloride Substances 0.000 description 3
- 235000010344 sodium nitrate Nutrition 0.000 description 3
- 239000004317 sodium nitrate Substances 0.000 description 3
- XVNRSQASUCMHGX-UHFFFAOYSA-N O[Si](O)(O)O.OP(O)(O)=O Chemical compound O[Si](O)(O)O.OP(O)(O)=O XVNRSQASUCMHGX-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 238000010422 painting Methods 0.000 description 2
- 230000037452 priming Effects 0.000 description 2
- 229910052761 rare earth metal Inorganic materials 0.000 description 2
- 150000002910 rare earth metals Chemical class 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- PITMOJXAHYPVLG-UHFFFAOYSA-N 2-acetyloxybenzoic acid;n-(4-ethoxyphenyl)acetamide;1,3,7-trimethylpurine-2,6-dione Chemical compound CCOC1=CC=C(NC(C)=O)C=C1.CC(=O)OC1=CC=CC=C1C(O)=O.CN1C(=O)N(C)C(=O)C2=C1N=CN2C PITMOJXAHYPVLG-UHFFFAOYSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 1
- XSTXAVWGXDQKEL-UHFFFAOYSA-N Trichloroethylene Chemical group ClC=C(Cl)Cl XSTXAVWGXDQKEL-UHFFFAOYSA-N 0.000 description 1
- 238000007792 addition Methods 0.000 description 1
- 238000013019 agitation Methods 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 239000003518 caustics Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000006193 liquid solution Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 235000021110 pickles Nutrition 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 239000011253 protective coating Substances 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- UBOXGVDOUJQMTN-UHFFFAOYSA-N trichloroethylene Natural products ClCC(Cl)Cl UBOXGVDOUJQMTN-UHFFFAOYSA-N 0.000 description 1
- 238000009966 trimming Methods 0.000 description 1
- 229940099259 vaseline Drugs 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
- This invention relates in general to a coating for magnesium and magnesium alloys, and in particular to an initial immersion coating for magnesium and magnesium alloys which facilitates and enhances subsequent priming and painting coatings for these materials.
- a chemical conversion coating or an electrochemical coating is necessary as a paint base for magnesium.
- Current chemical conversion coatings commonly employ some means other' than immersion for contacting the surface of the magnesium material.
- the current methods of coating involve a surface spray, electrochemical application or manual application. In addition to being costly methods of application, these chemical conversion coatings do not produce uniform results.
- the coatings can be marred by pitting in electrochemical applications.
- the coatings can be powdery or of erratic thicknesses when spraying or manual methods of application are employed.
- One method of immersion coating magnesium materials although using a solid Vaseline instead of a liquid solution, is given in Patent 2,671,736 by Zoeller. This process involves a costly heating step in order to obtain an impregnated petroleum coating. From this discussion, there is evident in the prior art an absence of a liquid immersion solution to serve as a chemical conversion coating for magnesium materials.
- a further object of this invention is a chemical conversion coating with uniform, powder-free surfaces on magnesium and magnesium alloys.
- a further object of this invention is a less reactive and more easily controlled chemical conversion coating.
- this invention is a method of promoting reaction on the surfaces of magnesium and magnesium alloys with a resultant compound formation which promotes subsequent decorative or protective coatings.
- This compound formation on the surfaces of magnesium materials is uniform, powder-free and pit-free, and it consists of a magnesium dichromate compound as formed by soluble dichrom-ate ions contacting magnesium material while being catalyzed -by soluble sulfate ions in an adjustable defined pH range.
- This chemical conversion coating was devised specifically for rare-earth magnesium alloys.
- An example of of such an aloy is HK31A.
- the development of the coating solution was specifically for rare-earth magnesium alloys, the solution works adequately for all magnesium and magnesium alloy materials.
- the aqueous solution range is as follows:
- the proportionate remainder is water.
- the immersion time is 2 to 10 minutes
- the temperature is ambient or room temperature
- the mild agitation of the solution is done by filtered air.
- Example 1 This example is provided as being typical and illustrative and in no manner shall serve to limit our coating process to this specific instance.
- the magnesium material (HK31A, for instance) is first degreased in trichloroethylene.
- a cleaning solution is employed to remove foreign substances from the surface of the magnesium material.
- the magnesium material is immersed in the following aqueous chemical conversion coating solution:
- the solution should be mildly agitated with filtered air.
- the time of immersion is 3 to 10 minutes if the solution is agitated as described above.
- the solution is used at ambient temperatures. When the solution becomes saturated with magnesium, usually around three ounces per gallon, it is no longer effective.
- the pH is adjusted to the lower limit on synthesis of the solution and maintained within the above stated range by chromic acid additions.
- the magnesium material is rinsed as given above and allowed to dry, completing the chemical conversion coating. Storage of the conversion coated magnesium material is important as it should be a kept as clean and dry as possible until primed and painted.
- a coating process for magnesium and magnesium alloys in preparation for subsequent applications of coatings comprising the steps of deg-reasing, cleaning, pickling in a solution comprised of:
- a coating process for magnesium and magnesium alloys in preparation for subsequent applications of coatings comprising the steps of degreasing, cleaning, pickling in a solution comprised initially of:
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- 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)
- Application Of Or Painting With Fluid Materials (AREA)
Description
United States Patent 3,301,719 CHEMICAL CONVERSION COATING FOR MAGNESIUM Earl C. Groshart and James B. Mohler, Seattle, Wash, assignors to The Boeing Company, Seattle, Wash., a corporation of Delaware No Drawing. Filed Oct. 15, 1962, Ser. No. 230,669
2 Claims. (Cl. 148-6.21)
This invention relates in general to a coating for magnesium and magnesium alloys, and in particular to an initial immersion coating for magnesium and magnesium alloys which facilitates and enhances subsequent priming and painting coatings for these materials.
A chemical conversion coating or an electrochemical coating is necessary as a paint base for magnesium. Current chemical conversion coatings commonly employ some means other' than immersion for contacting the surface of the magnesium material. The current methods of coating involve a surface spray, electrochemical application or manual application. In addition to being costly methods of application, these chemical conversion coatings do not produce uniform results. The coatings can be marred by pitting in electrochemical applications. The coatings can be powdery or of erratic thicknesses when spraying or manual methods of application are employed. One method of immersion coating magnesium materials, although using a solid Vaseline instead of a liquid solution, is given in Patent 2,671,736 by Zoeller. This process involves a costly heating step in order to obtain an impregnated petroleum coating. From this discussion, there is evident in the prior art an absence of a liquid immersion solution to serve as a chemical conversion coating for magnesium materials.
Therefore it is an object of this invention to provide a liquid immersion solution to serve as a chemical conversion coating for magnesium and magnesium alloys.
A further object of this invention is a chemical conversion coating with uniform, powder-free surfaces on magnesium and magnesium alloys.
A further object of this invention is a less reactive and more easily controlled chemical conversion coating.
Further objects and advantages of this invention as well as its use and operation will be apparent from the following descriptions and claims.
In its most common usage, this invention is a method of promoting reaction on the surfaces of magnesium and magnesium alloys with a resultant compound formation which promotes subsequent decorative or protective coatings. This compound formation on the surfaces of magnesium materials is uniform, powder-free and pit-free, and it consists of a magnesium dichromate compound as formed by soluble dichrom-ate ions contacting magnesium material while being catalyzed -by soluble sulfate ions in an adjustable defined pH range.
This chemical conversion coating was devised specifically for rare-earth magnesium alloys. An example of of such an aloy is HK31A. Although the development of the coating solution was specifically for rare-earth magnesium alloys, the solution works adequately for all magnesium and magnesium alloy materials.
The aqueous solution range is as follows:
Sodium dichromate dihydrate, ounces/gallon 4 to 8 Sodium sulfate, ounces/ gallon 0.5 to 0.8 pH 1.6 to 1.9
The proportionate remainder is water. With this solution, the immersion time is 2 to 10 minutes, the temperature is ambient or room temperature, and the mild agitation of the solution is done by filtered air.
We have found that a broad variable range of concentrations of dichromate dihydrate ions and sulfate ions "ice with some permissible variations in the pH range are possible in producing an effective coating solution. However the above solution has been found to operate efiectively as a magnesium coating medium. Therefore the operating characteristics of the full range of constituents have not been determined as a matter of economy. The operating characteristics of the above defined range have been fully determined for our uses.
The following is a description of the procedure used to coat magnesium and magnesium alloys. After fabrication and trimming of the material, the part is degreased and allowed to dry. An alkaline cleaner, a mediumduty phosphate-silicate cleaner, follows, as improperly cleaned areas will not be coated. After cleaning, the magnesium material is pickled (i.e., corroded surface areas are removed). Rinsing in warm water (130 F. to 150 F.) prepares the magnesium material for immersion in the coating solution. Rinsing and drying the material after coating completes the application of the chemical conversion coating. Storage of the coated parts is very important as the magnesium material should be kept as clean as possible until priming and painting are complete.
Example This example is provided as being typical and illustrative and in no manner shall serve to limit our coating process to this specific instance.
The magnesium material (HK31A, for instance) is first degreased in trichloroethylene.
A cleaning solution is employed to remove foreign substances from the surface of the magnesium material.
- The best cleaning solutions that we have found are medium-duty phosphate-silicate cleaners, but aluminum cleaners and heavy-duty silicate caustic cleaners also function properly.
Picking accomplishes removal of the heavily corroded areas of the magnesium material and contributes greatly to successful and reliable coatings.
The following aqueous chrome-nitrate pickle is used:
Chromic acid, ounces/ gallon 40 to 50 Sodium nitrate, ounces/ gallon 3.5 to 4.5 Sodium chloride (chloride ion), parts per million, maximum 10 Temperature, F. Time, minutes in solution 5 to9 Rinsing insures proper uniform action of the coating solution and for this reason the magnesium material should be rinsed prior to contact with the coating solution. A rinse in warm water (130 F. to F.) for three minutes immersion or 8 to 10 minutes in a water spray is suflicient.
The magnesium material is immersed in the following aqueous chemical conversion coating solution:
Sodium dichromate dihydrate, ounces/gallon 6 Sodium sulfate, ounce/ gallon 0.65 pH 1.6 to 1.9
For effective operation the solution should be mildly agitated with filtered air. The time of immersion is 3 to 10 minutes if the solution is agitated as described above. The solution is used at ambient temperatures. When the solution becomes saturated with magnesium, usually around three ounces per gallon, it is no longer effective. The pH is adjusted to the lower limit on synthesis of the solution and maintained within the above stated range by chromic acid additions.
Following the coating, the magnesium material is rinsed as given above and allowed to dry, completing the chemical conversion coating. Storage of the conversion coated magnesium material is important as it should be a kept as clean and dry as possible until primed and painted.
We claim:
1. A coating process for magnesium and magnesium alloys in preparation for subsequent applications of coatings comprising the steps of deg-reasing, cleaning, pickling in a solution comprised of:
Chromic acid, ounces per gallon 40 to 50 Sodium nitrate, ounces per gallon 3.5 to 4.5 Sodium chloride (or chloride ion), parts per million, maximum 10 Water, balance rinsing, contacting with a coating solution of:
Sodium dichromate dihydrate 4 to 8 ounces per gallon Sodium sulfate 0.5 to 0.8 ounce per gallon Chromic acid Sufiicient to maintain the pH within 1.6 to 1.9
Water, balance and thereafter rinsing the part.
2. A coating process for magnesium and magnesium alloys in preparation for subsequent applications of coatings comprising the steps of degreasing, cleaning, pickling in a solution comprised initially of:
Chromic acid, ounces per gallon 50 Sodium nitrate, ounces per gallon 4.5 Sodium chloride (or chloride ion), parts per million,
maximum Water, balance 4 rinsing, contacting with a coating solution comprised initially of: 7
Sodium dichromate dihydrate 6 ounces per gallon Sodium sulfate 0.65 ounce per gallon Chromic acid Suflicient to maintain the pH Within 1.6 to 1.9 Water, balance and thereafter rinsing the part.
References Cited by the Examiner OTHER REFERENCES A.P.C., application of Seibel et al., Ser. No. 3,151,184, published May 11, 1943.
ALFR-ED L. LEAVITT, Primary Examiner.
WILLIAM D. MA RTIN, RALPH S. KENDALL,
Examiners.
Claims (1)
1. A COATING PROCESS FOR MAGNESIUM AND MAGNESIUM ALLOYS IN PREPARATION FOR SUBSEQUENT APPLICATIONS OF COATINGS COMPRISING THE STEPS OF DEGREASING, CLEANING, PICKLING IN A SOLUTION COMPRISED OF:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US230669A US3301719A (en) | 1962-10-15 | 1962-10-15 | Chemical conversion coating for magnesium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US230669A US3301719A (en) | 1962-10-15 | 1962-10-15 | Chemical conversion coating for magnesium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3301719A true US3301719A (en) | 1967-01-31 |
Family
ID=22866123
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US230669A Expired - Lifetime US3301719A (en) | 1962-10-15 | 1962-10-15 | Chemical conversion coating for magnesium |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US3301719A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4070193A (en) * | 1975-09-19 | 1978-01-24 | Kaddis Mfg. Co. | Corrosion resistant metal sealing formulation |
| US4592854A (en) * | 1985-01-09 | 1986-06-03 | Mcdonnell Douglas Corporation | Steel etchant |
| US4915782A (en) * | 1988-12-21 | 1990-04-10 | Mcdonnell Douglas Corporation | Aluminum lithium etchant |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1747776A (en) * | 1929-04-19 | 1930-02-18 | Firm Dr Otto Sprenger Patentve | Production of dark oxidic coatings on magnesium and magnesium alloys |
| US2154451A (en) * | 1934-12-17 | 1939-04-18 | Du Pont | Bright dip |
| US2224528A (en) * | 1937-12-23 | 1940-12-10 | Sutton Hubert | Protection of magnesium and magnesium alloys |
| US2454799A (en) * | 1944-12-09 | 1948-11-30 | Hart David | Method of producing protective coatings on magnesium powder |
| US2480448A (en) * | 1943-04-28 | 1949-08-30 | Permanente Metals Corp | Protective surface treatment of magnesium base alloys |
| US2483510A (en) * | 1945-04-14 | 1949-10-04 | United Chromium Inc | Composition for dip coating solution and dip process for coloring zinc |
| US2796372A (en) * | 1953-05-07 | 1957-06-18 | Poor & Co | Corrosion protecting metal finishing composition |
| US2854371A (en) * | 1956-02-01 | 1958-09-30 | Shwayder Bros Inc | Method and solution for treatment of magnesium articles |
| US2861019A (en) * | 1956-06-07 | 1958-11-18 | Dow Chemical Co | Chromate-coating magnesium and its alloys |
| US3094489A (en) * | 1959-08-31 | 1963-06-18 | Monsanto Chemicals | Method and composition for brightening aluminum |
-
1962
- 1962-10-15 US US230669A patent/US3301719A/en not_active Expired - Lifetime
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1747776A (en) * | 1929-04-19 | 1930-02-18 | Firm Dr Otto Sprenger Patentve | Production of dark oxidic coatings on magnesium and magnesium alloys |
| US2154451A (en) * | 1934-12-17 | 1939-04-18 | Du Pont | Bright dip |
| US2224528A (en) * | 1937-12-23 | 1940-12-10 | Sutton Hubert | Protection of magnesium and magnesium alloys |
| US2480448A (en) * | 1943-04-28 | 1949-08-30 | Permanente Metals Corp | Protective surface treatment of magnesium base alloys |
| US2454799A (en) * | 1944-12-09 | 1948-11-30 | Hart David | Method of producing protective coatings on magnesium powder |
| US2483510A (en) * | 1945-04-14 | 1949-10-04 | United Chromium Inc | Composition for dip coating solution and dip process for coloring zinc |
| US2796372A (en) * | 1953-05-07 | 1957-06-18 | Poor & Co | Corrosion protecting metal finishing composition |
| US2854371A (en) * | 1956-02-01 | 1958-09-30 | Shwayder Bros Inc | Method and solution for treatment of magnesium articles |
| US2861019A (en) * | 1956-06-07 | 1958-11-18 | Dow Chemical Co | Chromate-coating magnesium and its alloys |
| US3094489A (en) * | 1959-08-31 | 1963-06-18 | Monsanto Chemicals | Method and composition for brightening aluminum |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4070193A (en) * | 1975-09-19 | 1978-01-24 | Kaddis Mfg. Co. | Corrosion resistant metal sealing formulation |
| US4592854A (en) * | 1985-01-09 | 1986-06-03 | Mcdonnell Douglas Corporation | Steel etchant |
| US4915782A (en) * | 1988-12-21 | 1990-04-10 | Mcdonnell Douglas Corporation | Aluminum lithium etchant |
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