US3923612A - Electroplating a gold-platinum alloy and electrolyte therefor - Google Patents
Electroplating a gold-platinum alloy and electrolyte therefor Download PDFInfo
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- US3923612A US3923612A US445740A US44574074A US3923612A US 3923612 A US3923612 A US 3923612A US 445740 A US445740 A US 445740A US 44574074 A US44574074 A US 44574074A US 3923612 A US3923612 A US 3923612A
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- alkali metal
- gold
- solution
- hexahydroxyplatinate
- platinum
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- JUWSSMXCCAMYGX-UHFFFAOYSA-N gold platinum Chemical compound [Pt].[Au] JUWSSMXCCAMYGX-UHFFFAOYSA-N 0.000 title claims abstract description 15
- 229910001260 Pt alloy Inorganic materials 0.000 title claims abstract description 13
- 238000009713 electroplating Methods 0.000 title abstract description 15
- 239000003792 electrolyte Substances 0.000 title description 7
- 229910052783 alkali metal Inorganic materials 0.000 claims abstract description 40
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims abstract description 40
- 150000001340 alkali metals Chemical class 0.000 claims abstract description 39
- 239000000243 solution Substances 0.000 claims abstract description 31
- 229910052737 gold Inorganic materials 0.000 claims abstract description 22
- 239000010931 gold Substances 0.000 claims abstract description 22
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims abstract description 21
- 229910052697 platinum Inorganic materials 0.000 claims abstract description 19
- 239000008151 electrolyte solution Substances 0.000 claims description 14
- 238000004070 electrodeposition Methods 0.000 claims description 8
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 claims description 4
- ALHHYLLHZKAXCW-UHFFFAOYSA-H dipotassium;platinum(4+);hexahydroxide Chemical compound [OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[K+].[K+].[Pt+4] ALHHYLLHZKAXCW-UHFFFAOYSA-H 0.000 claims description 4
- 229910052700 potassium Inorganic materials 0.000 claims description 4
- 239000011591 potassium Substances 0.000 claims description 4
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims description 3
- 238000000034 method Methods 0.000 claims description 3
- 229910052708 sodium Inorganic materials 0.000 claims description 3
- 239000011734 sodium Substances 0.000 claims description 3
- LDMNYTKHBHFXNG-UHFFFAOYSA-H disodium;platinum(4+);hexahydroxide Chemical compound [OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[Na+].[Na+].[Pt+4] LDMNYTKHBHFXNG-UHFFFAOYSA-H 0.000 claims description 2
- 230000008021 deposition Effects 0.000 abstract description 7
- 239000007864 aqueous solution Substances 0.000 abstract description 3
- 229910045601 alloy Inorganic materials 0.000 description 16
- 239000000956 alloy Substances 0.000 description 16
- 239000000203 mixture Substances 0.000 description 7
- 238000000151 deposition Methods 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- 238000007747 plating Methods 0.000 description 6
- 150000002739 metals Chemical class 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- 229910001369 Brass Inorganic materials 0.000 description 3
- 239000010951 brass Substances 0.000 description 3
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 3
- 238000005260 corrosion Methods 0.000 description 3
- -1 e.g. Substances 0.000 description 3
- 229910001020 Au alloy Inorganic materials 0.000 description 2
- XFXPMWWXUTWYJX-UHFFFAOYSA-N Cyanide Chemical compound N#[C-] XFXPMWWXUTWYJX-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- QRJOYPHTNNOAOJ-UHFFFAOYSA-N copper gold Chemical compound [Cu].[Au] QRJOYPHTNNOAOJ-UHFFFAOYSA-N 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 239000003353 gold alloy Substances 0.000 description 2
- 229960003975 potassium Drugs 0.000 description 2
- SCVFZCLFOSHCOH-UHFFFAOYSA-M potassium acetate Chemical compound [K+].CC([O-])=O SCVFZCLFOSHCOH-UHFFFAOYSA-M 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- LWIHDJKSTIGBAC-UHFFFAOYSA-K tripotassium phosphate Chemical compound [K+].[K+].[K+].[O-]P([O-])([O-])=O LWIHDJKSTIGBAC-UHFFFAOYSA-K 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910000881 Cu alloy Inorganic materials 0.000 description 1
- 241001397173 Kali <angiosperm> Species 0.000 description 1
- 229920000297 Rayon Polymers 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 229940045985 antineoplastic platinum compound Drugs 0.000 description 1
- 238000005282 brightening Methods 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- PQTCMBYFWMFIGM-UHFFFAOYSA-N gold silver Chemical compound [Ag].[Au] PQTCMBYFWMFIGM-UHFFFAOYSA-N 0.000 description 1
- 150000004820 halides Chemical class 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 150000002825 nitriles Chemical class 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 150000003058 platinum compounds Chemical class 0.000 description 1
- 235000011056 potassium acetate Nutrition 0.000 description 1
- 239000001508 potassium citrate Substances 0.000 description 1
- 229960002635 potassium citrate Drugs 0.000 description 1
- QEEAPRPFLLJWCF-UHFFFAOYSA-K potassium citrate (anhydrous) Chemical compound [K+].[K+].[K+].[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O QEEAPRPFLLJWCF-UHFFFAOYSA-K 0.000 description 1
- 235000011082 potassium citrates Nutrition 0.000 description 1
- 229910000160 potassium phosphate Inorganic materials 0.000 description 1
- 235000011009 potassium phosphates Nutrition 0.000 description 1
- 159000000001 potassium salts Chemical class 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000000742 single-metal deposition Methods 0.000 description 1
- 238000009987 spinning Methods 0.000 description 1
- 239000003115 supporting electrolyte Substances 0.000 description 1
- 230000002747 voluntary effect Effects 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
- C25D3/00—Electroplating: Baths therefor
- C25D3/02—Electroplating: Baths therefor from solutions
- C25D3/56—Electroplating: Baths therefor from solutions of alloys
- C25D3/62—Electroplating: Baths therefor from solutions of alloys containing more than 50% by weight of gold
Definitions
- C25D 3/62; C25D 3/56 substantially 0.5 to substantially 3.0 grams of gold per [58'] Field of Search 204/43 G, 43 N, 44, I23 liter.
- the bath is operated at a temperature preferably in the range of from substantially 50C to substantially [5 6] References Cited 65C.
- This invention relates to the electrodeposition of gold-platinum alloys.
- Gold-platinum alloys have been used for many yearsas spinning jets in the viscose rayon industry where theywithstand corrosive conditions and severe mechanical conditions for long periods.
- the gold-platinum alloys are also suitable for use as crucibles for alkaline fusions.
- Electrodeposition of alloys involves; more complicated processes than the deposition of ,pure metals. Alloy deposition is much more sensitive to a variety of factors than a'single metal. Variables-must be controlled much more closelythan in a single metal deposition in o'rderto obtain deposits of uniform color, corrosion resistance, composition and appearance. The supporting electrolyte must be chosen so that the reduction potential of the metals will, be fairly close. Indeed, it is often difficult to predict the composition of an alloy from thatof the electrolyte andfrom the plating conditions. I
- gold-platinum alloy deposits of consistently excellent quality canbe obtained by electrodeposition from an aqueous electroplating bath comprising an alkali metal hexahydroxyplatinate and an alkali metal aurate.
- concentration of the alkali metal hexahydroxyplatinate should be sufficiently high numin solution within the range of from substantially 19 to substantially 22 grams per liter is preferred, with the concentration of the alkali metal aurate being adjusted in accordance with the concentration of gold desired in the finaldeposit.
- Deposits containing from substan'tially 15% to substantially 95% gold can be obtained with the baths of the present invention.
- One of thevariables requiring control in the utilizationof the baths of the present invention is the pH of the solution. It is important that the electroplating bath be'highly alkalineythe pH of the solution should be maintained above substantially 11.0. If the pH of the solution-falls below substantially llIO, the alkali metal hexahydroxyplatinate tends to form a precipitate.
- the solutions preparedby dissolving an alkali metal hexahydroxyplatinate and an alkali metal aurate have a sufficiently high pH for use in the present invention, but, if necessary, the pH of the solution can be adjusted before and/or during use by the addition of suitable amounts of water-soluble alkaline acting substances such as alkali metal'salts of weak acids, e.g., phosphoric acid, acetic acid or citric acid.
- weak acids e.g., phosphoric acid, acetic acid or citric acid.
- the plating temperature affects not only the structure and appearance-of theelectrodeposited alloys but also theirchemic'al"composition. 'Ingeneral, the preferred temperature is in the range of from substantially 50C to substantially 65C.
- an electroplating bath for the electrodeposition of goldplatinum alloys comprising an alkali metal-hexahydroxyplatinate and tion.”
- the aqueous electroplating bath comprises from substantially 15 and from substantially 0.5 to substantially 3.0, preferably from substantially 1.0 to substantially 2.0, grams per liter of gold as sodium or potassiumaurate, the pH of the solution being maintained at above substantially l 1.0, preferably above substantially ll.5.
- the operatingconditions suitable for any particular plating -application may be readily' determined by one skilled in the art.
- the average cathode current density used will depend upon the alloy desired and on the shape and size of the article to be plated. It is preferable an alkali metal aurate i'n aqueous soluto employ cathode current densities of below substantially 20 amperes/ft? preferably substantially 5 to substantially 8 amperes/ft under normal direct current plating conditions, with a deposition rate of from substantially 0.0002 to substantially 0.00025 inch/hr.
- the electrolyte solution is used with insoluble platinum or platinum clad anodes, and it is necessary to replenish the gold and platinum deposited from the electrolyte solution by addition of fresh gold and platinum compounds.
- water-soluble alkaline substances such as alkali metal salts of weak acids, e.g., potassium phosphate, potassium acetate, or potassium citrate can be added before and/or during use in sufficient quantities to maintain the pH of the solution in the required range.
- Suitable brightening agents which are well known in the art, can be added from time to time to maintain the desired physical characteristics of the alloy deposited.
- the electrolyte of the present invent-ion is operated at temperature of substantially 50C to substantially 65C.
- EXAMPLE I A 250 m1. aqueous electroplating solution was prepared containing 21 grams per liter of platinum as K Pt( OH) and 0.7 grams per liter of gold as KAuO The .pH .of the solution was above 11.5. The bath was operated at a temperature of 55C. The electrolyte was used to plate clean brass parts. The composition of the deposited alloy was 10% Au-90% Pt. The deposit was found to be smooth.
- EXAM PLE An aqueous electroplating solution was prepared as in Example 1, except that theconcentration of gold present (as KAuO was 2.8 grams per liter. The electrolyte was used to plate clean brass parts. The bath was operated at a temperature of 65C. A current of 0.2 ampere was employed. The composition of the final deposit was 30% Pt-70% Au. The deposit was found to be of excellent quality.
- EXAMPLE III A 250 ml. aqueous electroplating solution was prepared containing grams per liter of platinum as K Pt(OH and 1.55 gram per liter of gold as KAuO The pH of the solution was above 1 1.5. The bath was operated at a temperature of 53C and 0.4 ampere was used to plate a clean brass panel. The final deposit contained 37.538% Pt.
- the electroplating solutions illustrated in the above examples can also be prepared with other alkali metal hexahydroxyplatinates, particularly Na Pt(OH) and 4 with other alkali metal aurates, particularly NaAuO
- the potassium salts are preferred.
- Alloy deposits containing from substantially 15% to substantially gold can be obtained by using electroplating baths similar to those illustrated above.
- the concentration of the alkali metal hexahydroxyplatinate should be such as to provide from substantially 15 to substantially 25 grams, and preferably from substantially 19 to substantially 22 grams, of platinum per liter of solution, with the concentration of the alkali metal aurate being adjusted to provide the desired concentration of gold in the final deposit.
- concentration of the alkali metal aurate to provide from substantially 0.5 to substantially 3.0 grams of gold per liter of solution will yield goldplatinum alloy deposits within the composition range contemplated by the present invention providing a constant current density is used.
- the platinum and gold contents in the bath must be carefully controlled as well as the current density.
- An aqueous electrolyte solution for the electrodeposition of gold-platinum alloys comprising an alkali metal hexahydroxyplatinate and an alkali metal aurate and wherein the pH of the solution is above substantially ll.0.
- alkali metal hexahydroxyplatinate is selected from the group consisting of sodium hexahydroxyplatinate and potassium hexahydroxyplatinate
- alkali metal aurate is selected from the group consisting of sodium aurate and potassium aurate.
- a process for the electrodeposition of goldplatinum alloys which comprises electrolyzing an aqueous electrolyte solution as claimed in claim 1 at a.temperature between substantially 50C and substantially 65C.
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electroplating And Plating Baths Therefor (AREA)
- Electroplating Methods And Accessories (AREA)
Abstract
An electroplating bath for the deposition of gold-platinum alloys comprising an aqueous solution of alkali metal hexahydroxyplatinate and alkali metal aurate. Preferably, the solution comprises sufficient alkali metal hexahydroxyplatinate to provide from substantially 15 to substantially 25 grams of platinum per liter and sufficient alkali metal aurate to provide from substantially 0.5 to substantially 3.0 grams of gold per liter. The bath is operated at a temperature preferably in the range of from substantially 50*C to substantially 65*C.
Description
United States Patent 1191 1111 B 3,923,612 Wiesner Dec. 2, 1975 54 l ELECTROPLATING A GOLD PLATINUM OTHER PUBLICATIONS ALLOY AND ELECTROLYTE THEREFOR [75] Inventor: Harold J. Wiesner, Livermore, Graham et Plating 148453 (1949). Calif.
[73] Assignee: The United States of America as Primary Examiner cemld L Kaplan represented by the Umted states Attorney, Agent, or Firm-John A. Horan; Frederick Energy Research and Development A. Robartson; Irene Croft Administration, Washington, DC.
[22] Filed: Feb. 25, I974 [57] ABSTRACT [2] 1 Appl' 445740 An electroplating bath for the deposition of gold- [44] Published under the Trial Voluntary Protest platinum alloys comprising an aqueous solution of al- Program on January 28, 1975 as document no. kali metal hexahydroxyplatinate and alkali metal au- B 445,740. rate. Preferably, the solution comprises sufficient alkali metal hexahydroxyplatinate to provide from sub- [52] US. Cl. 204/43 G; 75/165; 75/172; stantially 15 to substantially 25 grams of platinum per 204/43 N liter and sufficient alkali metal aurate to provide from [51] Int. CI. C25D 3/62; C25D 3/56 substantially 0.5 to substantially 3.0 grams of gold per [58'] Field of Search 204/43 G, 43 N, 44, I23 liter. The bath is operated at a temperature preferably in the range of from substantially 50C to substantially [5 6] References Cited 65C.
FOREIGN PATENTS OR APPLICATIONS 6/1963 United Kingdom 204/43 G 6 Claims, N0 Drawings ELECTROPLATING A GOLD-PLATINUM ALLOY AND ELECTROLYTE THEREFOR BACKGROUND OF THE INVENTIQN The invention described herein was made in the course of, or under, Contract No; W-7405-ENG-48 with the United States Atomic Energy Commission.
This invention relates to the electrodeposition of gold-platinum alloys. I
For the last two decades great impetus to gold plating research has been given ,by the requirements of the electronics and allied industries that specified thicker coatings of greater hardness, wearresistance, corrosion resistance and lower porosity; Another field which is opening for electrodeposited gold alloys is that of high temperature applications. Electroplated gold-copper alloys have been investigated for this purpose --but, in general, a major disadvantage. ofthesealloys is their poormechanical properties at high temperature. Also, the low-density copper component undesirably decreases the density of the alloy. Of the binaryalloysinvestigated for high temperatureuse, gold-platinum alloys have been found to be the most suitable. Platinum hardens gold very effectivelyand also increases its resistance to oxidation and-corrosion. Gold-platinum alloys have been used for many yearsas spinning jets in the viscose rayon industry where theywithstand corrosive conditions and severe mechanical conditions for long periods. The gold-platinum alloys arealso suitable for use as crucibles for alkaline fusions.
Electrodeposition of alloys involves; more complicated processes than the deposition of ,pure metals. Alloy deposition is much more sensitive to a variety of factors than a'single metal. Variables-must be controlled much more closelythan in a single metal deposition in o'rderto obtain deposits of uniform color, corrosion resistance, composition and appearance. The supporting electrolyte must be chosen so that the reduction potential of the metals will, be fairly close. Indeed, it is often difficult to predict the composition of an alloy from thatof the electrolyte andfrom the plating conditions. I
to insure deposition of platinum on the cathode. It has been found that a'concentration of alkali metal hexahydroxyplatinate sufficient to provide from substantially to substantially grams of platinum'per liter of aqueous solution is eminently suitablefor use in the present invention. For best results, an amount of plati- Electrodepositionprocedures for such gold alloys as v gold-copper and goldsilver alloys, generally employ cyanide complex solutions. However, metals of the platinum group are not deposited from aqueous cyanide solutions since the cyanide complexes of these metals are so stable thattheir deposition on the cathodeis either impossible, or possible only at very low eurrent densities. Investigations of the depositionofgold-platinum alloys from halide systems were made and reported by A. K. Graham, S. Heiman, and H. L. Pinkerton, flaring,
SUMMARY-OF THE INVENTION.
It has been found that gold-platinum alloy deposits of consistently excellent quality canbe obtained by electrodeposition from an aqueous electroplating bath comprising an alkali metal hexahydroxyplatinate and an alkali metal aurate. The concentration of the alkali metal hexahydroxyplatinateshould be sufficiently high numin solution within the range of from substantially 19 to substantially 22 grams per liter is preferred, with the concentration of the alkali metal aurate being adjusted in accordance with the concentration of gold desired in the finaldeposit. Deposits containing from substan'tially 15% to substantially 95% gold can be obtained with the baths of the present invention. For high temperature applications, alloy deposits containing from substantially=% to substantially gold are generally preferred. One of thevariables requiring control in the utilizationof the baths of the present invention is the pH of the solution. It is important that the electroplating bath be'highly alkalineythe pH of the solution should be maintained above substantially 11.0. If the pH of the solution-falls below substantially llIO, the alkali metal hexahydroxyplatinate tends to form a precipitate. Generally, the solutions preparedby dissolving an alkali metal hexahydroxyplatinate and an alkali metal aurate have a sufficiently high pH for use in the present invention, but, if necessary, the pH of the solution can be adjusted before and/or during use by the addition of suitable amounts of water-soluble alkaline acting substances such as alkali metal'salts of weak acids, e.g., phosphoric acid, acetic acid or citric acid.
- Another variable requiring control is the plating temperature'The temperature affects not only the structure and appearance-of theelectrodeposited alloys but also theirchemic'al"composition. 'Ingeneral, the preferred temperature is in the range of from substantially 50C to substantially 65C.
DETAILED DESCRIPTION OF THE INVENTION According to the present invention, there is provided an electroplating bath for the electrodeposition of goldplatinum alloys comprising an alkali metal-hexahydroxyplatinate and tion." 1
In a specific embodiment of the invention, the aqueous electroplating bath comprises from substantially 15 and from substantially 0.5 to substantially 3.0, preferably from substantially 1.0 to substantially 2.0, grams per liter of gold as sodium or potassiumaurate, the pH of the solution being maintained at above substantially l 1.0, preferably above substantially ll.5.
The operatingconditions suitable for any particular plating -application may be readily' determined by one skilled in the art. The average cathode current density used will depend upon the alloy desired and on the shape and size of the article to be plated. It is preferable an alkali metal aurate i'n aqueous soluto employ cathode current densities of below substantially 20 amperes/ft? preferably substantially 5 to substantially 8 amperes/ft under normal direct current plating conditions, with a deposition rate of from substantially 0.0002 to substantially 0.00025 inch/hr.
Generally, the electrolyte solution is used with insoluble platinum or platinum clad anodes, and it is necessary to replenish the gold and platinum deposited from the electrolyte solution by addition of fresh gold and platinum compounds.
As stated above, it is important that the pH of the solution be maintained above substantially l 1.0, and preferably above substantially l 1.5, to prevent precipitation of the alkali metal hexahydroxyplatinate. lf necessary, water-soluble alkaline substances such as alkali metal salts of weak acids, e.g., potassium phosphate, potassium acetate, or potassium citrate can be added before and/or during use in sufficient quantities to maintain the pH of the solution in the required range. Suitable brightening agents, which are well known in the art, can be added from time to time to maintain the desired physical characteristics of the alloy deposited.
For best results, the electrolyte of the present invent-ion is operated at temperature of substantially 50C to substantially 65C. I
The following examples are illustrative of the electroplating solutions of the present invention.
, EXAMPLE I A 250 m1. aqueous electroplating solution was prepared containing 21 grams per liter of platinum as K Pt( OH) and 0.7 grams per liter of gold as KAuO The .pH .of the solution was above 11.5. The bath was operated at a temperature of 55C. The electrolyte was used to plate clean brass parts. The composition of the deposited alloy was 10% Au-90% Pt. The deposit was found to be smooth.
. EXAM PLE [I An aqueous electroplating solution was prepared as in Example 1, except that theconcentration of gold present (as KAuO was 2.8 grams per liter. The electrolyte was used to plate clean brass parts. The bath was operated at a temperature of 65C. A current of 0.2 ampere was employed. The composition of the final deposit was 30% Pt-70% Au. The deposit was found to be of excellent quality.
EXAMPLE III A 250 ml. aqueous electroplating solution was prepared containing grams per liter of platinum as K Pt(OH and 1.55 gram per liter of gold as KAuO The pH of the solution was above 1 1.5. The bath was operated at a temperature of 53C and 0.4 ampere was used to plate a clean brass panel. The final deposit contained 37.538% Pt.
EXAMPLE [V A bath containing 2.0 g/lAu (as KAuO and about 20 g/l Pt as K Pt(OH) operated at 5355C and a current of 0.2 amperes produced a deposit containing 55% Pt.
The electroplating solutions illustrated in the above examples can also be prepared with other alkali metal hexahydroxyplatinates, particularly Na Pt(OH) and 4 with other alkali metal aurates, particularly NaAuO However, from a long range stability standpoint, the potassium salts are preferred.
Alloy deposits containing from substantially 15% to substantially gold can be obtained by using electroplating baths similar to those illustrated above. For best results, the concentration of the alkali metal hexahydroxyplatinate should be such as to provide from substantially 15 to substantially 25 grams, and preferably from substantially 19 to substantially 22 grams, of platinum per liter of solution, with the concentration of the alkali metal aurate being adjusted to provide the desired concentration of gold in the final deposit. Generally, varying the concentration of the alkali metal aurate to provide from substantially 0.5 to substantially 3.0 grams of gold per liter of solution will yield goldplatinum alloy deposits within the composition range contemplated by the present invention providing a constant current density is used. Thus, to maintain a specific alloy composition, the platinum and gold contents in the bath must be carefully controlled as well as the current density.
Although the invention has been described with reference to specific examples, it will be appreciated that various modifications and changes will be evident to those skilled in the art without departing from' the true spirit and scope thereof. Thus, it is not intended to limit the invention except by the terms of the following claims.
What 1 claim is:
1. An aqueous electrolyte solution for the electrodeposition of gold-platinum alloys comprising an alkali metal hexahydroxyplatinate and an alkali metal aurate and wherein the pH of the solution is above substantially ll.0.
2. An electrolyte solution as claimed in claim 1 wherein the alkali metal hexahydroxyplatinate is selected from the group consisting of sodium hexahydroxyplatinate and potassium hexahydroxyplatinate, and the alkali metal aurate is selected from the group consisting of sodium aurate and potassium aurate.
3. An electrolyte solution as claimed in claim 1 wherein the concentration of the alkali metal hexahydroxyplatinate is sufficient to provide from substantially 15 to substantially 25 grams of platinum per liter of solution.
4. An electrolyte solution as claimed in claim 1 wherein the concentration of the alkali metal aurate is sufficient to provide from substantially 0.5 to substantially 3.0 grams of gold per liter of solution.
5. An electrolyte solution as claimed in claim 1 wherein the alkali metal hexahydroxyplatinate is potassium hexahydroxyplatinate in a concentration sufficient to provide from substantially 19 to substantially 22 grams of platinum per liter of solution and the alkali metal aurate is potassium aurate in a concentration sufficient to provide from substantially 0.5 to substantially 3.0 grams of gold per liter of solution.
6. A process for the electrodeposition of goldplatinum alloys which comprises electrolyzing an aqueous electrolyte solution as claimed in claim 1 at a.temperature between substantially 50C and substantially 65C.
Claims (6)
1. AN AQUEOUS ELECTROLYTE SOLUTION FOR THE ELECTRODEPOSITION OF GOLD-PLATINUM ALLOYS COMPRISING AN ALKALI METAL HEXAHYDROXYPLATINATE AND AN ALKALI METAL AURATE AND WHEREIN THE PH OF THE SOLUTION IS ABOVE SUBSTANTIALLY 11.0.
2. An electrolyte solution as claimed in claim 1 wherein the alkali metal hexahydroxyplatinate is selected from the group consisting of sodium hexahydroxyplatinate and potassium hexahydroxyplatinate, and the alkali metal aurate is selected from the group consisting of sodium aurate and potassium aurate.
3. An electrolyte solution as claimed in claim 1 wherein the concentration of the alkali metal hexahydroxyplatinate is sufficient to provide from substantially 15 to substantially 25 grams of platinum per liter of solution.
4. An electrolyte solution as claimed in claim 1 wherein the concentration of the alkali metal aurate is sufficient to provide from substantially 0.5 to substantially 3.0 grams of gold per liter of solution.
5. An electrolyte solution as claimed in claim 1 wherein the alkali metal hexahydroxyplatinate is potassium hexahydroxyplatinate in a concentration sufficient to provide from substantially 19 to substantially 22 grams of platinum per liter of solution and the alkali metal aurate is potassium aurate in a concentration sufficient to provide from substantially 0.5 to substantially 3.0 grams of gold per liter of solution.
6. A process for the electrodeposition of gold-platinum alloys which comprises electrolyzing an aqueous electrolyte solution as claimed in claim 1 at a temperature between substantially 50*C and substantially 65*C.
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US445740A US3923612A (en) | 1974-02-25 | 1974-02-25 | Electroplating a gold-platinum alloy and electrolyte therefor |
GB231475A GB1448549A (en) | 1974-02-25 | 1975-01-20 | Gold-platinum plating bath |
FR7505861A FR2262132A1 (en) | 1974-02-25 | 1975-02-25 | |
JP50022529A JPS5110130A (en) | 1974-02-25 | 1975-02-25 | |
DE19752508130 DE2508130A1 (en) | 1974-02-25 | 1975-02-25 | GOLD-PLATINUM PLATING BATH |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US445740A US3923612A (en) | 1974-02-25 | 1974-02-25 | Electroplating a gold-platinum alloy and electrolyte therefor |
Publications (2)
Publication Number | Publication Date |
---|---|
USB445740I5 USB445740I5 (en) | 1975-01-28 |
US3923612A true US3923612A (en) | 1975-12-02 |
Family
ID=23770021
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US445740A Expired - Lifetime US3923612A (en) | 1974-02-25 | 1974-02-25 | Electroplating a gold-platinum alloy and electrolyte therefor |
Country Status (5)
Country | Link |
---|---|
US (1) | US3923612A (en) |
JP (1) | JPS5110130A (en) |
DE (1) | DE2508130A1 (en) |
FR (1) | FR2262132A1 (en) |
GB (1) | GB1448549A (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4358350A (en) * | 1980-06-10 | 1982-11-09 | Degussa Ag | Strongly acid gold alloy bath |
US5310475A (en) * | 1990-06-29 | 1994-05-10 | Electroplating Engineers Of Japan, Limited | Platinum electroforming and platinum electroplating |
US6558581B2 (en) * | 1997-10-23 | 2003-05-06 | Sumitomo Metal Mining Co., Ltd. | Transparent electro-conductive structure, process for its production, transparent electro-conductive layer forming coating fluid used for its production, and process for preparing the coating fluid |
US20060178260A1 (en) * | 2005-02-04 | 2006-08-10 | Chuan-Jian Zhong | Gold-based alloy nanoparticles for use in fuel cell catalysts |
US20080226917A1 (en) * | 2007-02-20 | 2008-09-18 | Research Foundation Of State University Of New York | Core-shell nanoparticles with multiple cores and a method for fabricating them |
US7829140B1 (en) | 2006-03-29 | 2010-11-09 | The Research Foundation Of The State University Of New York | Method of forming iron oxide core metal shell nanoparticles |
US11674234B1 (en) | 2020-09-30 | 2023-06-13 | National Technology & Engineering Solutions Of Sandia, Llc | Electrodeposited platinum-gold alloy |
US20230211375A1 (en) * | 2020-04-15 | 2023-07-06 | Hewlett-Packard Development Company, L.P. | Coated substrates for electronic devices |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2478512B1 (en) * | 1980-03-24 | 1985-03-22 | Charmilles Sa Ateliers | |
US4513191A (en) * | 1980-05-13 | 1985-04-23 | Inoue-Japax Research Incorporated | Method of and apparatus for resetting a wire electrode in an operating setup on an electroerosion machine |
CH636291A5 (en) * | 1980-07-15 | 1983-05-31 | Charmilles Sa Ateliers | METHOD AND DEVICE FOR INSERTING THE TIP OF A WIRE ELECTRODE INTO THE STARTING PORT OF A PIECE TO BE CUT BY EROSIVE SPARKING. |
JPH04333588A (en) * | 1990-07-16 | 1992-11-20 | Electroplating Eng Of Japan Co | Production of high-hardness platinum material and its material |
JP2577832B2 (en) * | 1990-06-29 | 1997-02-05 | 日本エレクトロプレイテイング・エンジニヤース株式会社 | Platinum electroforming bath |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB928083A (en) * | 1961-04-28 | 1963-06-06 | Johnson Matthey Co Ltd | Improvements in and relating to the electrodeposition of gold |
-
1974
- 1974-02-25 US US445740A patent/US3923612A/en not_active Expired - Lifetime
-
1975
- 1975-01-20 GB GB231475A patent/GB1448549A/en not_active Expired
- 1975-02-25 FR FR7505861A patent/FR2262132A1/fr not_active Withdrawn
- 1975-02-25 DE DE19752508130 patent/DE2508130A1/en active Pending
- 1975-02-25 JP JP50022529A patent/JPS5110130A/ja active Pending
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB928083A (en) * | 1961-04-28 | 1963-06-06 | Johnson Matthey Co Ltd | Improvements in and relating to the electrodeposition of gold |
Non-Patent Citations (1)
Title |
---|
A. K. Graham et al., Plating^, Vol. 2, pp. 148-153, (1949) * |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4358350A (en) * | 1980-06-10 | 1982-11-09 | Degussa Ag | Strongly acid gold alloy bath |
US5310475A (en) * | 1990-06-29 | 1994-05-10 | Electroplating Engineers Of Japan, Limited | Platinum electroforming and platinum electroplating |
US6558581B2 (en) * | 1997-10-23 | 2003-05-06 | Sumitomo Metal Mining Co., Ltd. | Transparent electro-conductive structure, process for its production, transparent electro-conductive layer forming coating fluid used for its production, and process for preparing the coating fluid |
US20060178260A1 (en) * | 2005-02-04 | 2006-08-10 | Chuan-Jian Zhong | Gold-based alloy nanoparticles for use in fuel cell catalysts |
US7208439B2 (en) * | 2005-02-04 | 2007-04-24 | The Research Foundation Of State University Of New York | Gold-based alloy nanoparticles for use in fuel cell catalysts |
US7829140B1 (en) | 2006-03-29 | 2010-11-09 | The Research Foundation Of The State University Of New York | Method of forming iron oxide core metal shell nanoparticles |
US20080226917A1 (en) * | 2007-02-20 | 2008-09-18 | Research Foundation Of State University Of New York | Core-shell nanoparticles with multiple cores and a method for fabricating them |
US8343627B2 (en) | 2007-02-20 | 2013-01-01 | Research Foundation Of State University Of New York | Core-shell nanoparticles with multiple cores and a method for fabricating them |
US9327314B2 (en) | 2007-02-20 | 2016-05-03 | The Research Foundation For The State University Of New York | Core-shell nanoparticles with multiple cores and a method for fabricating them |
US10006908B2 (en) | 2007-02-20 | 2018-06-26 | The Research Foundation For The State University Of New York | Core-shell nanoparticles with multiple cores and a method for fabricating them |
US10191042B2 (en) | 2007-02-20 | 2019-01-29 | The Research Foundation For The State University Of New York | Core-shell nanoparticles with multiple cores and method for fabricating them |
US20230211375A1 (en) * | 2020-04-15 | 2023-07-06 | Hewlett-Packard Development Company, L.P. | Coated substrates for electronic devices |
US11674234B1 (en) | 2020-09-30 | 2023-06-13 | National Technology & Engineering Solutions Of Sandia, Llc | Electrodeposited platinum-gold alloy |
Also Published As
Publication number | Publication date |
---|---|
FR2262132A1 (en) | 1975-09-19 |
DE2508130A1 (en) | 1975-08-28 |
GB1448549A (en) | 1976-09-08 |
JPS5110130A (en) | 1976-01-27 |
USB445740I5 (en) | 1975-01-28 |
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