[go: up one dir, main page]

US2847371A - Chromium plating on aluminum - Google Patents

Chromium plating on aluminum Download PDF

Info

Publication number
US2847371A
US2847371A US518663A US51866355A US2847371A US 2847371 A US2847371 A US 2847371A US 518663 A US518663 A US 518663A US 51866355 A US51866355 A US 51866355A US 2847371 A US2847371 A US 2847371A
Authority
US
United States
Prior art keywords
aluminum
article
chromium
hydrochloric acid
chromic
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
Application number
US518663A
Inventor
Paul J Topelian
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tiarco Corp
Original Assignee
Tiarco Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Tiarco Corp filed Critical Tiarco Corp
Priority to US518663A priority Critical patent/US2847371A/en
Application granted granted Critical
Publication of US2847371A publication Critical patent/US2847371A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/34—Pretreatment of metallic surfaces to be electroplated
    • C25D5/42—Pretreatment of metallic surfaces to be electroplated of light metals
    • C25D5/44—Aluminium
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
    • Y10T428/12736—Al-base component
    • Y10T428/12743—Next to refractory [Group IVB, VB, or VIB] metal-base component

Definitions

  • the invention relates to electroplating and is more particularly concerned with the conditioning or special treatment of aluminum and aluminum alloys preliminary to plating with chromium to provide a tightly adherent bond between the chromium and the aluminum base metal.
  • the invention is applicable to aluminum and its alloys.
  • Aluminum as hereinafter used in the specification and claims is intended in a generic sense to include both the commercially pure metal and alloys of the metal which are predominantly, or contain a substantial quantity of, aluminum.
  • reference to an article of aluminum is intended to include to include a base metal which is entirely of aluminum or some other metal, which is clad with, or has a surface layer of, aluminum.
  • the process in widest commercial use today for preparing an aluminum surface for plating is the zinc immersion process.
  • a thin and adherent film of metallic zinc or alloy of zinc replaces the aluminum oxide film.
  • the zinc. provides a surface which is more readily plated with other metals than the aluminum. Not all metals, however, may then be simply deposited directly on the zinc surface.
  • special precautions are necessary because the zinc layer is very thin and any treatment which penetrates the zinc layer and attacks the underlying aluminum will result in a poor deposit:
  • the plating When depositing chromium on the zincated surface, the plating must be kept at a low temperature, approximately 68 F., and then only a very thin layer of chromium may be applied. In order to produce thick and hard deposits of chromium a transition must be made to plate at a higher temperature.
  • the zinc immersion process for preparing an aluminum article for chromium plating has procedural limitations and is expensive.
  • One of the primary objects of theinvention is to provide an improved processfor plating chromium directly on to aluminum, with the resultant deposit so tightly adherent to the base metal that the finished product is capable of'withstandingthe rugged and severe conditions encountered in industrial or engineering applications or uses.
  • Another process for plating aluminum involves immersing the aluminum in a molten metallic salt bath preliminary to plating. Such process, however, because of the degree of heat involved, frequently has a deleterious aifect upon the aluminum, and has proved to be less than satisfactory for many applications.
  • chromium may be directly plated on to aluminum without impairing the physical properties of the aluminum, while permitting the attainment of a strong bond between the electrodeposit and the underlying aluminum. This is accomplished by conditioning the surface of the aluminum in an aqueous solution containing chromic acid, hydrochloric acid and a chloride'of chromium.
  • chromic acid and chromic chloride to hydrochloric acid seems to buffer or somehow modify the otherwise highly corrosive action of hydrochloric acid on aluminum to condition the surface in a manner which results in an unusually strong bond between the subsequent chromium deposit and the aluminum.
  • the effect of the hydrochloric acid may be additionally tempered by the addition of a small amount of potassium permanganate to the solution.
  • the solution is preferably subjected to electrolytic action, although no current is used when the aluminum article is immersed in the solution.
  • an aluminum article is degreased and cleaned in accordance with accept-ed praotices.
  • the article may be degreased in trichloroethylene and cleaned with any suitable commercial cleaner such as hot caustic soda.
  • the article is thoroughly rinsed in "cold water and then immersed in nitric-acid of approximately sixty percent (60%) concentration for a period of ten 10) to fifteen (15) seconds, which turns the surface of the aluminum to a white color.
  • the article is then very thoroughly rinsed, and immersed in the conditioning solution of my invention.
  • the conditioning solution to achieve firm adherence of electrodeposit to base metal is prepared by dissolving chromic acid in hydrochloric acid, which may be commercial muriatic acid having a concentration of approximately 20 B.
  • hydrochloric acid which may be commercial muriatic acid having a concentration of approximately 20 B.
  • three and one-quarter (3 /4) pounds of chromicacid may be dissolved in five (5) gallons of the hydrochloric acid, or approximately ten (10) ounces per gallon of hydrochloric acid.
  • the chromic acid must be added to the hydrochloric acid in very small amounts at a time, otherwise the reaction will become un controllably' violent.. In any event, strong gassing takes place, and for the amounts stated twenty-four (24) to thirty-six (36 hours should be allowed for the contents ofthe tank to stop gassing.
  • Chromic chloride is added to the chromic acid-hydrochloric acid mixture.
  • Metallic chromium in an amount of approximately eight (8) ounces may be partially dissolvedinlOOO cc. of hydrochloric acid C. P., and added to the chromic acid-hydrochloric acid mixture.
  • a small amount of potassium permanganate may be added to the hydro- 'chloric acid solution containing the partially dissolved metallic chromium before combining with the chromic acid-hydrochloric acid mixture.
  • electrolytic cook and this is done by placing a pair of carbon rods, each having a surface area of approximately twenty (20) square inches in a tank containing thedescribed solution, connecting the rods to the cathode and anodev terminals of a rectifier, set at four (4) volts, and electrolyzing the solution for several hours. After cooling to room temperature, the solution is ready for use in the line.
  • the aluminum article is immersed in the foregoingsolution for approximately sixty (60), seconds. In about ten (10) seconds gassing action starts and increases rapidly. When the article is removed from the solution, after about sixty (60) seconds, the entire aluminum surface is literally bubbling, and has a grey appearance. The article is then thoroughly rinsed in cold water, preferably applied under high pressure, and is now ready for chromium plating.
  • Any commercial chromium plating. solution may be used. It is preferred, however, to plate in ahard chromium plating bath containing thirty-three (33) ounces'per gallon of chromic acid and 0.33 ounce pergallon of sulfate in the form of sulphuric acid. The bath is maintained at a temperature of approximately 132 F., and a current density of approximately three 3) amperes ,per square inch is used. The time of plating depends upon the thickness of chromium deposit desired, plating under the conditions stated furnishing a thickness of 0.001 inch per hour.
  • the article After plating the article is ve ry thoroughly rinsed in cold running water, and then rinsed in hot water and allowed to dry.
  • the chromium on the aluminum article After final deposition of the chromium on the aluminum article, it is preferred to heat the plated article at approximately three hundred (300 F.) degrees for one (1) to two (2) hours in a furnaceor by immersing the article in hot oil.
  • the chromium deposit may be subjected to a grinding wheel without displaying any cracking. or peeling of the plate. Upon bending the plated article, no crackingor;
  • a process of electroplating an aluminum article with chromium comprising immersing the article in an aqueous solution containing chromic acid, hydrochloric acid and chromic chloride, the ingredients being present in the approximate proportions ofthree (3) pounds of chromic acid, five (5) gallons of hydrochloric acid having 3.
  • a process of electroplating an aluminum article with chromium comprising immersing the article in an aqueous solution containing chromic acid, hydrochloric acid, chromic chloride and potassium permanganate in the approximate proportions of three (3) pounds of chromic acid, five (5) gallons of hydrochloric acid having a concentration of about 20 B., ten (10) to twenty (20) ounces of chromic chloride and one-half /2) ounce of potassium permanganate, removing the article from the solution after gassing occurs, and electroplating the article with chromium.
  • An aqueous solution for preparing an aluminum article for direct electroplating with chromium comprising chromic acid, hydrochloric acid and chromic chloride, the ingredientsbeing present inthe approximate proportions of three (3) pounds of chromic acid, five (5 gallons of hydrochloric acid having a concentration .of about 20 B. and ten (10) to twenty (20) ounces of chromic chloride.
  • An aqueous solution for preparing an aluminum article, for direct electroplating with chromium comprising chromic acid, hydrochloric acid, chromic chlon'de and potassium permanganate in the approximate proportions of-three (3) pounds of chromic acid, five (5) gallons of hydrochloric acid having a concentration of about 20 B., ten 10) to twenty (20) ounces of chromic chloride and one-half /2) ounce of potassium permanganate.
  • a process of electroplating an aluminum article with chromium comprising immersing the article in an aqueous solution made by. mixing chromic acid and hydrochloric acid, in the amounts of approximately ten (10) ounces of chromic acid per gallon of hydrochloric acid, the hydrochloric acid having a concentration of approximately 20' B., removing the article from the solution after gassing occurs, rinsing, and electroplating the article with chromium.
  • a process of electroplating, an aluminum article with chromium comprising irnrriersing the article in an aqueous solution containing chromic acid, hydrochloric acid and chromic chloride, the ingredients being present in the approximate proportions of. three (3) pounds of chromic acid, five (5) gallons of hydrochloric acid having a concentration of about 20 B. and ten (10) to twenty (20) ounces of chromic chloride, the period of immersion being approximately sixty (60) seconds, rinsing the article in water, and electroplating the article with chromium.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Electroplating Methods And Accessories (AREA)

Description

2,847,371 CHROMIUM PLATING N ALUMINUM Paul J. Topelian, Newark, N. J., assignor to Tiarco Corporation, Newark, N. J a corporation of New Jersey No Drawing. Application June 28, 1955 Serial No. 518,663
'10 Claims. (Cl. 204-63) The invention relates to electroplating and is more particularly concerned with the conditioning or special treatment of aluminum and aluminum alloys preliminary to plating with chromium to provide a tightly adherent bond between the chromium and the aluminum base metal.
The invention is applicable to aluminum and its alloys. Aluminum, as hereinafter used in the specification and claims is intended in a generic sense to include both the commercially pure metal and alloys of the metal which are predominantly, or contain a substantial quantity of, aluminum. Also, reference to an article of aluminum is intended to include to include a base metal which is entirely of aluminum or some other metal, which is clad with, or has a surface layer of, aluminum.
Much effort has been expended in the endeavor to obtain a tightly adherent deposit of chromium on aluminum. The metal is highly oxidizing in character, and presents an aluminum oxide film which is not receptive to a strongly adherent electrodeposit. Various methods have been suggested for preparing or conditioning an aluminum surface to make it receptive for electroplating.
The process in widest commercial use today for preparing an aluminum surface for plating is the zinc immersion process. In this process a thin and adherent film of metallic zinc or alloy of zinc replaces the aluminum oxide film. The zinc. provides a surface which is more readily plated with other metals than the aluminum. Not all metals, however, may then be simply deposited directly on the zinc surface. Where it is desired to deposit chromium upon the zincated aluminum, special precautions are necessary because the zinc layer is very thin and any treatment which penetrates the zinc layer and attacks the underlying aluminum will result in a poor deposit: When depositing chromium on the zincated surface, the plating must be kept at a low temperature, approximately 68 F., and then only a very thin layer of chromium may be applied. In order to produce thick and hard deposits of chromium a transition must be made to plate at a higher temperature. The zinc immersion process for preparing an aluminum article for chromium plating has procedural limitations and is expensive.
One of the primary objects of theinvention is to provide an improved processfor plating chromium directly on to aluminum, with the resultant deposit so tightly adherent to the base metal that the finished product is capable of'withstandingthe rugged and severe conditions encountered in industrial or engineering applications or uses.
It has been proposed to replace the natural aluminum oxide by arelatively thick porous oxide film formed by anodic treatment of the aluminum. This approach to the problem is based on the idea that the plating metal will adhere better to the aluminum through the medium of a controlled oxide film. The results of this method, however, have not afforded maximum adhesion of plated metal to base metal.
States PatentO 2,847,371 Patented Aug. 12, 1958 Special plating solutions have been devised to permit the direct plating on aluminum; however, none of the electrodeposits resulting from such solutions have furnished 'a truly satisfactory bond of the plate to base metal.
Another process for plating aluminum involves immersing the aluminum in a molten metallic salt bath preliminary to plating. Such process, however, because of the degree of heat involved, frequently has a deleterious aifect upon the aluminum, and has proved to be less than satisfactory for many applications.
It has also been proposed to prepare the aluminum for direct plating by preliminarily etching the aluminum, the idea being to develop a keying or mechanical inter-locking between the roughtened aluminum surface and the underlying plate. This method is difficult to control, and has not furnished uniformly satisfactory adherence between the plate and the base metal.
In accordance with my invention chromium may be directly plated on to aluminum without impairing the physical properties of the aluminum, while permitting the attainment of a strong bond between the electrodeposit and the underlying aluminum. This is accomplished by conditioning the surface of the aluminum in an aqueous solution containing chromic acid, hydrochloric acid and a chloride'of chromium. The addition of chromic acid and chromic chloride to hydrochloric acid seems to buffer or somehow modify the otherwise highly corrosive action of hydrochloric acid on aluminum to condition the surface in a manner which results in an unusually strong bond between the subsequent chromium deposit and the aluminum. The effect of the hydrochloric acid may be additionally tempered by the addition of a small amount of potassium permanganate to the solution. Also, the solution is preferably subjected to electrolytic action, although no current is used when the aluminum article is immersed in the solution.
Describing the invention in greater detail, an aluminum article is degreased and cleaned in accordance with accept-ed praotices." The article may be degreased in trichloroethylene and cleaned with any suitable commercial cleaner such as hot caustic soda. After the alkaline cleaning step,,the article is thoroughly rinsed in "cold water and then immersed in nitric-acid of approximately sixty percent (60%) concentration for a period of ten 10) to fifteen (15) seconds, which turns the surface of the aluminum to a white color. The article is then very thoroughly rinsed, and immersed in the conditioning solution of my invention.
The conditioning solution to achieve firm adherence of electrodeposit to base metal is prepared by dissolving chromic acid in hydrochloric acid, which may be commercial muriatic acid having a concentration of approximately 20 B. In terms of a solution of sufiicient quantity for commercial use, three and one-quarter (3 /4) pounds of chromicacid may be dissolved in five (5) gallons of the hydrochloric acid, or approximately ten (10) ounces per gallon of hydrochloric acid. The chromic acid must be added to the hydrochloric acid in very small amounts at a time, otherwise the reaction will become un controllably' violent.. In any event, strong gassing takes place, and for the amounts stated twenty-four (24) to thirty-six (36 hours should be allowed for the contents ofthe tank to stop gassing.
Chromic chloride is added to the chromic acid-hydrochloric acid mixture. Metallic chromium in an amount of approximately eight (8) ounces may be partially dissolvedinlOOO cc. of hydrochloric acid C. P., and added to the chromic acid-hydrochloric acid mixture.
A small amount of potassium permanganate, approxi- ,matelyone-half /2) ounce, may be added to the hydro- 'chloric acid solution containing the partially dissolved metallic chromium before combining with the chromic acid-hydrochloric acid mixture. As an alternative, chromic chloride crystals inan amount of ten (10) to twenty (20) ounces, and'thepotassium permanganate, may be added to the chromic acid-hydrochloricacid mix= ture. Approximately three (3) gallons of; water is then added, and the solution is allowed to stand for four (4) to six (6) hours before it is ready to receive aluminum pieces for treatment.
It is preferred to subject the described solution to an,
electrolytic cook, and this is done by placing a pair of carbon rods, each having a surface area of approximately twenty (20) square inches in a tank containing thedescribed solution, connecting the rods to the cathode and anodev terminals of a rectifier, set at four (4) volts, and electrolyzing the solution for several hours. After cooling to room temperature, the solution is ready for use in the line.
The aluminum article is immersed in the foregoingsolution for approximately sixty (60), seconds. In about ten (10) seconds gassing action starts and increases rapidly. When the article is removed from the solution, after about sixty (60) seconds, the entire aluminum surface is literally bubbling, and has a grey appearance. The article is then thoroughly rinsed in cold water, preferably applied under high pressure, and is now ready for chromium plating.
Any commercial chromium plating. solution may be used. It is preferred, however, to plate in ahard chromium plating bath containing thirty-three (33) ounces'per gallon of chromic acid and 0.33 ounce pergallon of sulfate in the form of sulphuric acid. The bath is maintained at a temperature of approximately 132 F., and a current density of approximately three 3) amperes ,per square inch is used. The time of plating depends upon the thickness of chromium deposit desired, plating under the conditions stated furnishing a thickness of 0.001 inch per hour.
After plating the article is ve ry thoroughly rinsed in cold running water, and then rinsed in hot water and allowed to dry.
After final deposition of the chromium on the aluminum article, it is preferred to heat the plated article at approximately three hundred (300 F.) degrees for one (1) to two (2) hours in a furnaceor by immersing the article in hot oil.
Aluminum articles preliminarily treated: in the described solution and then chromium plated provides an unusually adherent deposit to theunderlying aluminum. The chromium deposit may be subjected to a grinding wheel without displaying any cracking. or peeling of the plate. Upon bending the plated article, no crackingor;
peeling of the plate occurs.
It is believed that the novel process of the present invention, as well as the advantages thereof will be apparent from the foregoing detailed description. It will also be apparent that while the invention has been described in several preferred forms, changes may be made without departing fromthe spirit and scope of the invention, as sought to be defined in the following. claims.
I claim:
1. A process of electroplating an aluminum article with chromium comprising immersing the article in an aqueous solution containing chromic acid, hydrochloric acid and chromic chloride, the ingredients being present in the approximate proportions ofthree (3) pounds of chromic acid, five (5) gallons of hydrochloric acid having 3. A process of electroplating an aluminum article with chromium comprising immersing the article in an aqueous solution containing chromic acid, hydrochloric acid, chromic chloride and potassium permanganate in the approximate proportions of three (3) pounds of chromic acid, five (5) gallons of hydrochloric acid having a concentration of about 20 B., ten (10) to twenty (20) ounces of chromic chloride and one-half /2) ounce of potassium permanganate, removing the article from the solution after gassing occurs, and electroplating the article with chromium.
4. A process as set forth in claim 3, wherein the solution is electrolyzed prior to immersion of the aluminum article therein, there being no current applied when the article is immersed.
5. An aqueous solution for preparing an aluminum article for direct electroplating with chromium comprising chromic acid, hydrochloric acid and chromic chloride, the ingredientsbeing present inthe approximate proportions of three (3) pounds of chromic acid, five (5 gallons of hydrochloric acid having a concentration .of about 20 B. and ten (10) to twenty (20) ounces of chromic chloride.
6. An aqueous solution for preparing an aluminum article, for direct electroplating with chromium comprising chromic acid, hydrochloric acid, chromic chlon'de and potassium permanganate in the approximate proportions of-three (3) pounds of chromic acid, five (5) gallons of hydrochloric acid having a concentration of about 20 B., ten 10) to twenty (20) ounces of chromic chloride and one-half /2) ounce of potassium permanganate.
7. A process of electroplating an aluminum article with chromium comprising immersing the article in an aqueous solution made by. mixing chromic acid and hydrochloric acid, in the amounts of approximately ten (10) ounces of chromic acid per gallon of hydrochloric acid, the hydrochloric acid having a concentration of approximately 20' B., removing the article from the solution after gassing occurs, rinsing, and electroplating the article with chromium.
8. A process as set forth in claim 7, wherein the solution contains a small amount of chromicchloride.
9. A process of electroplating, an aluminum article with chromium comprising irnrriersing the article in an aqueous solution containing chromic acid, hydrochloric acid and chromic chloride, the ingredients being present in the approximate proportions of. three (3) pounds of chromic acid, five (5) gallons of hydrochloric acid having a concentration of about 20 B. and ten (10) to twenty (20) ounces of chromic chloride, the period of immersion being approximately sixty (60) seconds, rinsing the article in water, and electroplating the article with chromium.
10. A process as set forth in claim 9, wherein the solution contains approximately one-half /2) ounce ofpotassium permanganate.
References Cited inthe file of this patent UNITED sTATEs PATENTS 1,789,523 Hahn Jan. 20, 1931 1,797,357 McCullough et al. Mar. 24, 1931 1,838,777 McCullough et al Dec. 29, 1931 1,988,645 Bowden Ian. 22, 1935 2,091,386 Viers Aug. 31, 1937 2,227,469 Thompson et' al Jan. 7, 1941 2,302,939 De Long Nov. 24, 1942' 2,311,623 Blackum et a1 Feb. 23, 1943 2,357,219 Mott Aug. 29, 1944 2,428,749 De Long Oct. 7, 1947' OTHER REFERENCES A Comprehensive Treatise on Inorganic and Theoretia cal Chemistry, Mellor, vol. 11, pages 230-231.

Claims (1)

1. A PROCESS OF ELECTROPLATING AN ALUMINUM ARTICLE WITH CHROMIUM COMPRISING IMMERSING THE ARTICLE IN AN AQUEOUS SOLUTION CONTAINING CHROMIC ACID, HYDROCHLORIC ACID AND CHROMIC CHLORIDE, THE INGREDIENTS BEING PRESENT BY CONVENTIONAL MEANS TO THE UPPER END OF THE CONDUCTOR IN THE APPROXIMATE PROPORTIONS OF THREE (3) POUNDS OF CHROMIC ACID, FIVE (5) GALLONS OF HYDROCHLORIC ACID HAVING A CONCENTRATION OF ABOUT 20* BE''. AND TEN (10) TO TWENTY (20) OUNCES OF CHROMIC CHLORIDE, REMOVING THE ARTICLE FROM THE SOLUTION AFTER GASSING OCCURS, AND ELECTROPLATING WITH CHROMIUM.
US518663A 1955-06-28 1955-06-28 Chromium plating on aluminum Expired - Lifetime US2847371A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US518663A US2847371A (en) 1955-06-28 1955-06-28 Chromium plating on aluminum

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US518663A US2847371A (en) 1955-06-28 1955-06-28 Chromium plating on aluminum

Publications (1)

Publication Number Publication Date
US2847371A true US2847371A (en) 1958-08-12

Family

ID=24064934

Family Applications (1)

Application Number Title Priority Date Filing Date
US518663A Expired - Lifetime US2847371A (en) 1955-06-28 1955-06-28 Chromium plating on aluminum

Country Status (1)

Country Link
US (1) US2847371A (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3082137A (en) * 1958-12-03 1963-03-19 Gen Motors Corp Method and composition for etching titanium
US3205051A (en) * 1962-05-25 1965-09-07 Robertson Co H H Light-colored porcelain-enameled aluminum articles and clad-aluminum sheets therefor
US4371430A (en) * 1979-04-27 1983-02-01 Printing Developments, Inc. Electrodeposition of chromium on metal base lithographic sheet
US4397716A (en) * 1982-04-09 1983-08-09 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Variable anodic thermal control coating
US4596760A (en) * 1979-04-27 1986-06-24 Ballarini John A Electrodeposition of chromium on metal base lithographic sheet
US4900398A (en) * 1989-06-19 1990-02-13 General Motors Corporation Chemical milling of titanium
US5436081A (en) * 1991-02-18 1995-07-25 Sumitomo Metal Industries, Ltd. Plated aluminum sheet having improved spot weldability
US10584411B2 (en) 2014-07-18 2020-03-10 United Technologies Corporation Chromium-enriched diffused aluminide

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1789523A (en) * 1924-08-14 1931-01-20 Chromeplate Inc Method of electrolytically depositing chromium
US1797357A (en) * 1928-03-29 1931-03-24 Ternstedt Mfg Co Chromium plating
US1838777A (en) * 1928-03-26 1931-12-29 Ternstedt Mfg Co Chromium plating
US1988645A (en) * 1931-01-07 1935-01-22 Maytag Co Method of preparing and plating an aluminum object
US2091386A (en) * 1935-08-01 1937-08-31 Eaton Detroit Metal Company Electroplating
US2227469A (en) * 1936-11-05 1941-01-07 John S Thompson Vapor treatment of metals
US2302939A (en) * 1941-01-17 1942-11-24 Dow Chemical Co Cleaning rolled magnesium articles
US2311623A (en) * 1941-02-06 1943-02-23 Aluminum Co Of America Surface treatment for aluminum
US2357219A (en) * 1942-01-10 1944-08-29 Joseph P Moran Corrosion-resistant ferrous alloys
US2428749A (en) * 1944-08-19 1947-10-07 Dow Chemical Co Surface treatment of magnesium alloys

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1789523A (en) * 1924-08-14 1931-01-20 Chromeplate Inc Method of electrolytically depositing chromium
US1838777A (en) * 1928-03-26 1931-12-29 Ternstedt Mfg Co Chromium plating
US1797357A (en) * 1928-03-29 1931-03-24 Ternstedt Mfg Co Chromium plating
US1988645A (en) * 1931-01-07 1935-01-22 Maytag Co Method of preparing and plating an aluminum object
US2091386A (en) * 1935-08-01 1937-08-31 Eaton Detroit Metal Company Electroplating
US2227469A (en) * 1936-11-05 1941-01-07 John S Thompson Vapor treatment of metals
US2302939A (en) * 1941-01-17 1942-11-24 Dow Chemical Co Cleaning rolled magnesium articles
US2311623A (en) * 1941-02-06 1943-02-23 Aluminum Co Of America Surface treatment for aluminum
US2357219A (en) * 1942-01-10 1944-08-29 Joseph P Moran Corrosion-resistant ferrous alloys
US2428749A (en) * 1944-08-19 1947-10-07 Dow Chemical Co Surface treatment of magnesium alloys

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3082137A (en) * 1958-12-03 1963-03-19 Gen Motors Corp Method and composition for etching titanium
US3205051A (en) * 1962-05-25 1965-09-07 Robertson Co H H Light-colored porcelain-enameled aluminum articles and clad-aluminum sheets therefor
US4371430A (en) * 1979-04-27 1983-02-01 Printing Developments, Inc. Electrodeposition of chromium on metal base lithographic sheet
US4596760A (en) * 1979-04-27 1986-06-24 Ballarini John A Electrodeposition of chromium on metal base lithographic sheet
US4397716A (en) * 1982-04-09 1983-08-09 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Variable anodic thermal control coating
US4900398A (en) * 1989-06-19 1990-02-13 General Motors Corporation Chemical milling of titanium
US5436081A (en) * 1991-02-18 1995-07-25 Sumitomo Metal Industries, Ltd. Plated aluminum sheet having improved spot weldability
US10584411B2 (en) 2014-07-18 2020-03-10 United Technologies Corporation Chromium-enriched diffused aluminide
US11987877B2 (en) 2014-07-18 2024-05-21 Rtx Corporation Chromium-enriched diffused aluminide coating

Similar Documents

Publication Publication Date Title
US2580773A (en) Method and composition for coating aluminum with zinc
US5246565A (en) High adherence copper plating process
USRE29739E (en) Process for forming an anodic oxide coating on metals
US7704366B2 (en) Pretreatment of magnesium substrates for electroplating
US2654701A (en) Plating aluminum
US2313756A (en) Method of electroplating magnesium
US2847371A (en) Chromium plating on aluminum
US1971761A (en) Protection of metals
US2541083A (en) Electroplating on aluminum
US2457059A (en) Method for bonding a nickel electrodeposit to a nickel surface
US2526544A (en) Method of producing a metallic coating on magnesium and its alloys
US4784732A (en) Electrolytic formation of an aluminum oxide layer
US2075623A (en) Zinc plating
US3207679A (en) Method for electroplating on titanium
US4196061A (en) Direct nickel-plating of aluminum
US3515650A (en) Method of electroplating nickel on an aluminum article
US3284323A (en) Electroplating of aluminum and its alloys
US2856333A (en) Electroplating
US3276974A (en) Anodizing process for the metal beryllium
US3235404A (en) Method and compositions for zinc coating aluminum
US2095519A (en) Method for producing galvanic coatings on aluminum or aluminum alloys
US2791553A (en) Method of electroplating aluminum
US2888387A (en) Electroplating
US2966448A (en) Methods of electroplating aluminum and alloys thereof
US2557823A (en) Method of forming a composite article comprising steel and silver