US2836552A - Treatment of nickel for electroplating chromium thereon - Google Patents
Treatment of nickel for electroplating chromium thereon Download PDFInfo
- Publication number
- US2836552A US2836552A US539000A US53900055A US2836552A US 2836552 A US2836552 A US 2836552A US 539000 A US539000 A US 539000A US 53900055 A US53900055 A US 53900055A US 2836552 A US2836552 A US 2836552A
- Authority
- US
- United States
- Prior art keywords
- nickel
- solution
- range
- chromium
- activating
- 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
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 title claims description 18
- 229910052804 chromium Inorganic materials 0.000 title claims description 17
- 239000011651 chromium Substances 0.000 title claims description 17
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 title description 38
- 229910052759 nickel Inorganic materials 0.000 title description 19
- 238000009713 electroplating Methods 0.000 title description 3
- 239000000243 solution Substances 0.000 claims description 16
- 230000003213 activating effect Effects 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 8
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims description 7
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Chemical compound O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 claims description 7
- 239000007864 aqueous solution Substances 0.000 claims description 5
- 238000004070 electrodeposition Methods 0.000 claims description 3
- 238000007747 plating Methods 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 5
- 150000002500 ions Chemical class 0.000 description 4
- 239000002253 acid Substances 0.000 description 3
- 239000003792 electrolyte Substances 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 229910000978 Pb alloy Inorganic materials 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 2
- -1 for example Chemical class 0.000 description 2
- 239000001117 sulphuric acid Substances 0.000 description 2
- 235000011149 sulphuric acid Nutrition 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000010960 commercial process Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000005323 electroforming Methods 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 150000003839 salts Chemical class 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
- C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
- C25D5/34—Pretreatment of metallic surfaces to be electroplated
- C25D5/38—Pretreatment of metallic surfaces to be electroplated of refractory metals or nickel
- C25D5/40—Nickel; Chromium
Definitions
- This invention relates to the preparation of nickel for electroplating chromium thereon.
- the primary object of this invention is to provide an improved procedure for activating nickel for electrodepositing chromium thereon and especially an activating procedure in which prolonged immersion in the activating solution will not adversely affect the parts being processed.
- the present invention provides an improved activating process and improved electrolytes for carrying out the process.
- the improved electrolytes employed in accordance with the invention comprise aqueous solutions of chromic acid together with minor proportions of other ions, such as sulfate, chloride, fluoride, silicouoride or fluosilicate ions. These ions may be added as acids or as salts, for example, alkali metal or alkaline earth metal salts.
- the nickel surface to be treated which may be a nickel article or a composite article comprising a base member on which is a coating of nickel, is immersed in the solution and electric current is applied with the nickel or nickel coated article the cathode.
- a preferred bath comprises 2 to 6 oz./gal.
- chromic acid may range from 1 to oz./gal. and the sulfate from .05 to .30 oz./gal.
- ions such as chloride, fluoride, silico-fluoride, or fiuosilicate are used in place of sulfate equivalent amounts are used.
- the nickel surface to be activated is employed as a cathode in the electrolyte.
- the anodes may be of any suitable material. Lead and lead alloy anodes are quite satisfactory. A voltage on the order of 3 to 4 is preferred for best results although satisfactory results may be obtained with other voltages, for example, those on the order of 2 to 6. An average current density of 5 a. s. f. is satisfactory under most conditions.
- the cut- 2,836,552 iatented May 27, 1958 ice rent density should be kept below that at which metallic chromium will be deposited or cloudy chromium deposits will be produced during the subsequent chromium plat ing operation. In view of the fact that chromium may start to deposit at about 40 a. s. f.
- average current densities of about 10 a. s. f are about as high as it is safe to go on most complicated shapes; otherwise the current density on some areas being treated may exceed 40 a. s. f.
- the preferred amperage is on the average of 4 to 6 per square foot, although the range of 2 to 12 is satisfactory under most conditions.
- Optimum results are obtained with electrolyzing times of 30 seconds to three minutes. Under some conditions, as when the nickel surface is already fairly active as it enters the bath, shorter times of only about 10 to 15 seconds may be employed. Longer times than three minutes may also be used.
- One important advantage of the present invention is that the parts may be left in the bath for prolonged periods up to 30 minutes or more.
- the parts may be plated with chromium by known procedures in any conventional or other chromium plating bath.
- a method of activating a surface of nickel for the electrodeposition of chromium thereon which comprises providing an aqueous solution consisting essentially of chromic acid Within the range of 2 to 6 ounces per gallon and sulfate within the range of .05 to .30 ounce per gallon, immersing the nickel in said solution, said solution being at a temperature within the range of about 60 to 160 F., and passing an electric current through said solution with the nickel as the cathode at a current density of about 2 to 12 amperes per square foot for a time within the range of about 30 seconds to three minutes.
- a process of activating a surface of nickel for the electrodeposition of chromium thereon which comprises providing an aqueous solution consisting essentially of chromic acid within the range of 2 to 6 ounces per gallon and sulfate within the range of .10 to .15 ounce per gallon, said solution being at a temperature within the range of 80 to 130 F., immersing the nickel in said solution, and passing an electric current through the solution with the nickel as cathode at a current density of about 4 to 6 amperes per square foot for a time within the range of 30 seconds to three minutes.
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)
- Electroplating And Plating Baths Therefor (AREA)
Description
United States Patent TREATMENT OF NICKEL FOR ELECTROPLATEN G CHROM'IUM THEREON James D. Patrick, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware No Drawing. Application October 6, 1955 Serial No. 539,000
2 Claims. (Cl. 204-440) This invention relates to the preparation of nickel for electroplating chromium thereon.
In commercial processes of plating chromium on nickel it is common practice to activate the nickel surface prior to chromium plating by cleaning the article in a solution of hydrochloric or sulphuric acid. The article or part may be merely dipped in an aqueous solution of either of these acids or the part being treated may be made cathodic in the solution. Normal time in the acid solution is quite short and if the parts remain in the activated solution too long unsatisfactory chromium plate results, thus making it necessary to remove the chromium plate and replate the parts. In the operation of automatic plating machines which are commonly used today the machine may be frequently stopped without warning and in case the parts are left too long in the activating solution defective chromium plating will result such that it will be necessary to reject the articles. Accordingly the primary object of this invention is to provide an improved procedure for activating nickel for electrodepositing chromium thereon and especially an activating procedure in which prolonged immersion in the activating solution will not adversely affect the parts being processed.
The present invention provides an improved activating process and improved electrolytes for carrying out the process. The improved electrolytes employed in accordance with the invention comprise aqueous solutions of chromic acid together with minor proportions of other ions, such as sulfate, chloride, fluoride, silicouoride or fluosilicate ions. These ions may be added as acids or as salts, for example, alkali metal or alkaline earth metal salts. The nickel surface to be treated, which may be a nickel article or a composite article comprising a base member on which is a coating of nickel, is immersed in the solution and electric current is applied with the nickel or nickel coated article the cathode. A preferred bath comprises 2 to 6 oz./gal. of chromic acid and from .10 to .15 oz./gal. of sulfate added as sulphuric acid. While these are the preferred concentrations considerable variation may be employed with satisfactory results. For example, the chromic acid may range from 1 to oz./gal. and the sulfate from .05 to .30 oz./gal. When other ions such as chloride, fluoride, silico-fluoride, or fiuosilicate are used in place of sulfate equivalent amounts are used.
The nickel surface to be activated is employed as a cathode in the electrolyte. The anodes may be of any suitable material. Lead and lead alloy anodes are quite satisfactory. A voltage on the order of 3 to 4 is preferred for best results although satisfactory results may be obtained with other voltages, for example, those on the order of 2 to 6. An average current density of 5 a. s. f. is satisfactory under most conditions. The cut- 2,836,552 iatented May 27, 1958 ice rent density should be kept below that at which metallic chromium will be deposited or cloudy chromium deposits will be produced during the subsequent chromium plat ing operation. In view of the fact that chromium may start to deposit at about 40 a. s. f. under certain combinations of the above variables, average current densities of about 10 a. s. f are about as high as it is safe to go on most complicated shapes; otherwise the current density on some areas being treated may exceed 40 a. s. f. For these reasons the preferred amperage is on the average of 4 to 6 per square foot, although the range of 2 to 12 is satisfactory under most conditions.
Optimum results have been obtained with bath temperatures on the order of to F. However, considerable variation is permissible and temperature ranges on the order of 60 to F. are satisfactory.
Optimum results are obtained with electrolyzing times of 30 seconds to three minutes. Under some conditions, as when the nickel surface is already fairly active as it enters the bath, shorter times of only about 10 to 15 seconds may be employed. Longer times than three minutes may also be used. One important advantage of the present invention is that the parts may be left in the bath for prolonged periods up to 30 minutes or more.
After the activating treatment the parts may be plated with chromium by known procedures in any conventional or other chromium plating bath.
Various changes and modifications may be made in the embodiments of my invention described herein without departing from the principles and spirit of the invention.
I claim:
1. A method of activating a surface of nickel for the electrodeposition of chromium thereon which comprises providing an aqueous solution consisting essentially of chromic acid Within the range of 2 to 6 ounces per gallon and sulfate within the range of .05 to .30 ounce per gallon, immersing the nickel in said solution, said solution being at a temperature within the range of about 60 to 160 F., and passing an electric current through said solution with the nickel as the cathode at a current density of about 2 to 12 amperes per square foot for a time within the range of about 30 seconds to three minutes.
2. A process of activating a surface of nickel for the electrodeposition of chromium thereon which comprises providing an aqueous solution consisting essentially of chromic acid within the range of 2 to 6 ounces per gallon and sulfate within the range of .10 to .15 ounce per gallon, said solution being at a temperature within the range of 80 to 130 F., immersing the nickel in said solution, and passing an electric current through the solution with the nickel as cathode at a current density of about 4 to 6 amperes per square foot for a time within the range of 30 seconds to three minutes.
References Cited in the file of this patent UNITED STATES PATENTS 1,827,247 Mason Oct. 13, 1931 2,182,244 Beall Dec. 5, 1939 FOREIGN PATENTS 255,421 Switzerland Jan. 17, 1949 OTHER REFERENCES Principles of Electroplating and Electroforming, Blum and Hogaboom (1949), publ. by McGraw-Hill Book (30., pp. 338-343 cited.
Claims (1)
1. A METHOD OF ACTIVATING A SURFACE OF NICKEL FOR THE ELECTRODEPOSITION OF CHROMIUM THEREON WHICH COMPRISES PROVIDING AN AQUEOUS SOLUTION CONSISTING ESSENTIALLY OF CHROMIC ACID WITHIN THE RANGE OF 2 TO 6 OUNCES PER GALLON AND SULFATE WITHIN THE RANGE OF .05 TO .30 OUNCE PER GALLON, IMMERSING THE NICKEL IN SAID SOLUTION, SAID SOLUTION BEING AT A TEMPERATURE WITHIN THE RANGE OF ABOUT 60* TO 160*F., AND PASSING AN ELECTRIC CURRENT THROUGH SAID SOLUTION WITH THE NICKEL AS THE CATHODE AT A CURRENT DENSITY OF ABOUT 2 TO 12 AMPERES PER SQUARE FOOT FOR A TIME WITHIN THE RANGE OF ABOUT 30 SECONDS TO THREE MINUTES.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US539000A US2836552A (en) | 1955-10-06 | 1955-10-06 | Treatment of nickel for electroplating chromium thereon |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US539000A US2836552A (en) | 1955-10-06 | 1955-10-06 | Treatment of nickel for electroplating chromium thereon |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2836552A true US2836552A (en) | 1958-05-27 |
Family
ID=24149327
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US539000A Expired - Lifetime US2836552A (en) | 1955-10-06 | 1955-10-06 | Treatment of nickel for electroplating chromium thereon |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2836552A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3259556A (en) * | 1964-09-28 | 1966-07-05 | Gen Dynamics Corp | Ribbon electroplating method |
| US20100155256A1 (en) * | 2007-01-17 | 2010-06-24 | Chang Gung University | Electroplating Process for Using Trivalent Chromium Electroplating Solution |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1827247A (en) * | 1927-10-18 | 1931-10-13 | Western Electric Co | Method of protecting metal surfaces |
| US2182244A (en) * | 1936-10-15 | 1939-12-05 | Frank H Beall | Chromium plating |
| CH255421A (en) * | 1943-11-13 | 1948-06-30 | United Chromium Inc | Process for the production of cracked, galvanic chrome coatings. |
-
1955
- 1955-10-06 US US539000A patent/US2836552A/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1827247A (en) * | 1927-10-18 | 1931-10-13 | Western Electric Co | Method of protecting metal surfaces |
| US2182244A (en) * | 1936-10-15 | 1939-12-05 | Frank H Beall | Chromium plating |
| CH255421A (en) * | 1943-11-13 | 1948-06-30 | United Chromium Inc | Process for the production of cracked, galvanic chrome coatings. |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3259556A (en) * | 1964-09-28 | 1966-07-05 | Gen Dynamics Corp | Ribbon electroplating method |
| US20100155256A1 (en) * | 2007-01-17 | 2010-06-24 | Chang Gung University | Electroplating Process for Using Trivalent Chromium Electroplating Solution |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3664933A (en) | Process for acid copper plating of zinc | |
| JP4857340B2 (en) | Pretreatment of magnesium substrate for electroplating | |
| US2746915A (en) | Electrolytic metal treatment and article | |
| US1971761A (en) | Protection of metals | |
| US3417005A (en) | Neutral nickel-plating process and bath therefor | |
| US2541083A (en) | Electroplating on aluminum | |
| US2457061A (en) | Method for bonding a nickel electrodeposit to a nickel surface | |
| GB1122795A (en) | Improvements in corrosion-resisting decorative chromium electrolytic deposits | |
| US2078868A (en) | Electroplating process | |
| US3207679A (en) | Method for electroplating on titanium | |
| US2431947A (en) | Formation of a strong bond between a ferrous metal surface and an electrodeposit of silver | |
| US3505183A (en) | Process and compositions for electroplating chromium | |
| US2836552A (en) | Treatment of nickel for electroplating chromium thereon | |
| US3202589A (en) | Electroplating | |
| US4617095A (en) | Electrolytic post treatment of chromium substrates | |
| US2739932A (en) | Electrodepositing chromium on aluminum | |
| US2706171A (en) | Stripping chromium plating from zinc electrolytically | |
| US2791553A (en) | Method of electroplating aluminum | |
| US2409983A (en) | Electrodeposition of indium | |
| US2092130A (en) | Anodic cleaning process | |
| US2557823A (en) | Method of forming a composite article comprising steel and silver | |
| EP0097643B1 (en) | Zinc-nickel electroplated article and method for producing the same | |
| US2561222A (en) | Electrolytic method of stripping nickel, chromium, copper, zinc, cadmium, silver, tin, and lead electrodeposits from ferrous basis metals, and compositions for use therein | |
| US4225397A (en) | New and unique aluminum plating method | |
| US2330170A (en) | Electrolytic polishing of metal |