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
  • C25D3/12—Electroplating: Baths therefor from solutions of nickel or cobalt
• • 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
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S29/00—Metal working
  • Y10S29/012—Method or apparatus with electroplating

Definitions

• ELECTRODERO SITION' WITHiNICKEI; Etienne L. A. Ctmi'n,,New Yiirli, NI Y.,.vand' Siren E. Hybin'ette' and'Herbert B: 'l-ayl'or;Wilmimfi ton; Del., assignors; by m'esne assignmentefipto Kenmore--Metajls Gorporation, a corporation 01 Delaware NdDrawiiig, Applicationlime 26;.1946 ⁇ Sbri'a'ITNO. 679,558
• An object of this invention is to produce a: ductile nickel plating on metalwhich can be drawn;
• the ductility of-the product obtainable by the process of this: invention goesconsider ably beyond the previous standards -of ductility; inthis art.
• plated article:- is considered 1 ductile ii itcan be hammered or bent: without cracking;
• plated articles may be made in whichthe product is so ductile that it may be drawn; several thousands of timesits: previous length and :the' drawn product can --still be bentgtwisted or braided-withoutcausingtheplating: tozcrack;
• Another'object oi thisinvention is xto produc'e: aenickelplating bath from nickel or:nickel salts,-. hydrofluoric acid and a buffering. agent which? has substantially the same throwing power as asulphate-chloride type of nickelplating bath;
• Another object 'of thiseinventionis to expedite the rate of electrod'eposition; of. nickel andzat; the same :time: attain generally improvedioperati- 1 ing characteristics;
• Another; object. of: the presentinvention is. to: produce; heavy deposits: of nickel on metal in; smooth condition; by; employing: a1 process and a bath .7 in. which the; nickel does. not i tree. as: heavily as in the priorart;
• the upper limit oi nickelcontent of the bath- is determined mainly by the solubility of the nickel' or" nickel: salt;
• a hig-11' rii(:le1 content favors the pro duction' of a ductile plate at -high current dem sitiesa-
• a low nickel content sueh as for example about iii-grams per liter, low currentdensities must be employed whichmight be une economical for commercial production How ever, asatiSfactoryplate may be obt'ained at ai slightly lower' nickel content.
• the buffer employed in: the bath is: prefer? ably boric acid 'althoug-he it quite possible that other bufiers; such as the more ex-p'ensive citric acid or tartaric acid, could be employe'di-l
• the boric acid besidesacting: as a buffer: also reacts with the nickelion in the bathito:- producei Sis complex nickel; salt possibly a fluorob'orateit Thus; it is preferable-toadd sonifiexcessgiof (the: boric acid over thatrequiredito react with?the: nickelin the-bath.
• the solubility oithe" nickel-or nickel salt in.:the bath increases as'th'e': pH value is'loweredf
• pH value is'loweredf
• at around a pH 1 ⁇ hydrogen inclusion in' the plating may cause brittleness.
• hydrogemj evolution is; increased at-.lower.:pH:values-.- Atzthevlower: pHl'va'lues one: obtains better: anode corrosion andixaismallert amount of bufferziscnecessaryx
• therhigheitspfie values the: ductility; ofi thezzproduct somewhat;
• the range of current density which can be employed is wide. It is well known that the more intensive the agitation of the solution and/or the' cathode, the higher is the current density which can be employed. Our invention enables us to employ current densities two to three times higher than generally is possible under the same conditions of agitation. (In the art, current density is always referred to the surface area of the cathode unless the anode is specified.) For the best ductility the current densities of from 3-50 amps. per square decimeter are advantageous. High current densities are known in one other type bath, i. e. the high chloride type bath. These baths have the disadvantages of having a very low pH and of being very corrosive and can only be used with special equipment and with special protection for the operation. For these reasons these baths have not gained wide popularity.
• the baths of the present invention do not suffer from these defects.
• wetting agent which minimizes the effect of the evolution of hydrogen on the plate and, therefore, aids in the production of a more ductile and pore-free plate.
• Mechanical vibrations may also be employed to minimize the effect of the evolution of hydrogen.
• a wetting agent which may be used is Duponol ME which is a fatty alcohol sulphate type of wetting agent.
• Other wetting agents of this type or of any type which will stand up in an acid solution with a high salt content may be employed. Examples of such wetting agents are: quaternary ammonium compounds such as lauryl pyradonium chloride, long chain polyethylene oxide compounds such as Carbowax, etc.
• ductility was also determined by making plates .002" thick on copper wire and bending the plated wire over a rod four times the diameter of the wire. The plate at the bend was dipped first in hydrochloric acid and then in sodium polysulphide, and then examined under a microscope. If no cracks were revealed there was considered to be a good ductile plate.
• a diameter steel wire plated according to Example 12 with 5% by weight of nickel and at a current density of 25-30 amperes per square decimeter was drawn from a length of 3 feet to 16,000 feet and in every stage of the drawing could be bent, flexed, twisted or otherwise worked.
• the drawn wire still contained 5% by weight of nickel as determined by chemical analysis.
• the resultant drawn wire was also more resistant to corrosion due to the fact that in the drawing process the nickel plating became denser and at the same time retained its continuity.
• the degree of ductility achieved by the present invention is due to the crystal structure of the nickel deposit. X-ray tests seem to show that the nickel crystals deposited from our bath are not'deposited one alongside the other in the form known as trees but that a sufficient number of the crystals are aligned parallel to the surface of the base material to form brick-like layers and that these layers flow with the base metal when drawn, whereas a normal crystal growth perpendicular to the surface of the base metal separates when the plating is drawn.
• Nickel plating baths in common usage cannot hold-much iron in solution with the result that if any appreciable amount of iron is introduced it will be precipitated.
• Most nickel anodes contain some iron which enters the solution continuously, only to be precipitated. It has heretofore often been found necessary to constantly filter the solution or provide a very deep electroplating tank so that the iron precipitate may settle to such a depth in the bath as to obviate the danger of its being stirred up during the carrying out of the plating process.
• my improved electroplating bath all iron entering into the solution from the anode (assumingthe anode is primarily nickel and contains some iron). will remain in solution, thus obviating the formation of an iron precipitate.
• the iron in solution will be plated out with the nickel and deposited on the cathode.
• iron may, by design, be added to the solution for the purpose of producing a plate consisting of a nickel iron alloy.
• certain of the anodes would be constituted of iron.
• the bath is such in its operation that cobalt may be intentionally introduced in the solution when an electrodeposition of cobalt is desired along with the nickel.
• the baths of the present invention may beemployed for producing bright plating and it is then possible to work with high current densities (up to 2 or more) compared to the commercial brightening baths.
• high current densities up to 2 or more
• This possibility of working with high current densities is the important advantage in baths of the present invention where brightening agents are added since it is well known in the art that the addition of brightening agents to the electroplating baths reduces the ductility of the plating.
• the particular bath employed when plating ac cordingto the present invention depends upon such factors as the ductility required, the rate of deposition required, and the character of the plating operations to be undertaken.
• the exact composition of the bath and the operating characteristics thereof for any particular set of requirements will be apparent to those skilled in theart.
• a method for producing a relatively ductile nickel plating on a metal base which comprises passing a current of less than 250 amperes per square decimeterfrom a nickel anode to themetal base to be plated through a bath formed essentially from a nickel compound, hydrofluoric acid, boric acid and water, said hydrofluoric acid reacting with said nickel compound to form a.
• said hydrofluoric acid being present in a quantity in excess of that required to convert said nickel compound to said complex nickel fluoride, said bath containing at least 30 grams or" nickel metal per liter, said excess hydrofluoric acid giving said bath a pH of f more than 1 and less than 6, the anions of said bath comprising essentially fluorides and borates.
• a method for producing a highly ductile nickel plating on a metal base which comprises passing a current of less than 250 amper S per square decimeter from a nickel anode to the metal base to be plated through a bath formed essentially from nickel carbonate, hydrofluoric acid, boric acid and water, said hydrofluoric acid reacting with said nickel carbonate to form a com plex nickel fluoride, said hydrofluoric acid being present in a quantity in excess of that required to convert said nickel carbonate to said complex nickel fluoride, said bath containing at least 30 grains of nickel metal per liter, said excess hydrofluoric acid giving said bath a pH of more than 1 and less than 6, the anions of said bath comprisin-g essentially fluorides and. borates.
• a method for producing a highly ductile nickel plating on a metal base which comprises passing a current of less than 250 amperes per square deoimeter from a nickel anode to the metal base to be plated through a bath formed essentially from nickel, hydrofluoric acid, boric acid and water, said hydrofluoric acid reacting with said nickel to form a complex nickel fluoride, said hydrofluoric acid being present in a quantity in excess of that required to convert said nickel to said complex nickel fluoride, said bath contain ing at least 30 grams of nickel metal per liter, said excess hydrofluoric acid giving said bath a pH of more than 1 and less than 6, the anions of said bath comprising essentially fluorides and borates.
• a method for producing a highly ductile nickel plating on a metal base which comprises passing a current of less than 250 ampcres per square decimeter from a nickel anode to the metal base tobe plated through a bath formed essentially from a nickel compound, hydrofluoric acid, boric acid and water, said hydrofluoric acid reacting with said nickel compound to form a complex nickel fluoride, said hydrofluoric acid being present in a quantity in excess of that required to convert said nickel compound to said complex nickel fluoride, said bath containing at least 30 grams of nickel metal per liter, and 20 60 grams of boric acid per liter, said excess of hydrofluoricacid giving said.
• a method for producing a highly ductile nickel plating on a metal base which comprises passing a current of less than 250 amperes per square decimeter from a nickel anode to the metal base to be plated through a bath formed essentially from a nickel compound, hydrofluoric acid, boric acid and water, said hydrofluoric acid reacting with said nickel compound to form a complex nickel fluoride, said hydrofluoric acid being present in a quantity in excess of that required to convert said nickel compound to said complex nickel fluoride, said bath containing from 42 to 60 grams of nickel metal per liter, said excess hydrofluoric acid giving said bath a pH of more than 1 and less than 6, the anions of said bath comprising essentially fluorides and borates.
• a method for producing a highly ductile nickel plating on a metal base which comprises passing a current of from to less than 250 amperes per square decimeter from a nickel anode to the metal base to be plated through a bath formed essentially from a nickel compound, hydrofluoric acid, boric acid and water, said hydrofluoric acid reacting with said nickel compound to form a complex nickel fluoride, said hydrofluoric acid being present in a quantity in excess of that required to convert said nickel compound to said complex nickel fluoride, said bath containing at least grams of nickel metal per liter, said excess hydrofluoric acid giving said bath a pH of more than 1 and less than 6, the anions of said bath compris- I ing essentially fluorides and borates.
• a method for producing a highly ductile nickel plating on a metal base which comprises passing a current of from 15 to less than 250 amperes per square decimeter from a nickel an ode to the metal base to be plated through a bath formed essentially from a nickel compound, hydrofluoric acid, boric acid and water, said hydrofluoric acid reacting with said nickel compound to form a complex nickel fluoride, said hydrofluoric acid being present in a quantity in excess of that required to convert said nickel compound to said complex nickel fluoride, said bath containing from 42 to 60 grams of nickel metal per liter, said excess hydrofluoric acid giving said bath a pH of more than 1 and less than 6, the anions of said bath comprising essentially fluorides and borates.
• a bath for the electrodepositicn of a relatively ductile nickel coating on a metal base which is formed essentially from a nickel compound, hydrofluoric acid, boric acid and water, said hydrofluoric acid reacting with said nickel compound to form a complex nickel fluoride, said hydrofluoric acid being present in a quantity in excess of that required to convert said nickel compound to said complex nickel fluoride, said bath containing at least 30 grams of nickel metal per liter, said excess of hydrofluoric acid giving said bath a pH of more than 1 and less than 6, the anions of said bath comprising essentially fluorides and borates, said bath producing said relatively ductile nickel coating when operated at current densities of less than 250 amperes per square decimeter.
• a bath for the electrodepositicn of a highly ductile nickel coating on a metal base which is formed essentially from nickel carbonate, hydrofluoric acid, boric acid and water, said hydrofluoric acid reacting with said nickel carbonate to form a complex nickel fluoride, said hydrofluoric acid being present in a quantity in excess of that required to convert said nickel carbonate to said complex nickel fluoride, said bath containing at least 30 grams of nickel metal per liter, said excess hydrofluoric acid giving said bath a pH of more than 1 and less than 6,, the anions of said bath comprising essentially fluorides and borates, said bath producing said highly ductile nickel coating when operated at current densities of less than 250 amperes per square decimeter.
• a bath for the electrodepositicn of a highly ductile nickel coating on a metal base which is formed essentially from nickel, hydrofluoric acid, boric acid and water, said hydrofluoric acid reacting with said nickel to form a complex nickel fluoride, said hydrofluoric acid being present in a quantity in excess of that required to convert said nickel to said complex nickel fluoride, said bath containing at least 30 grams of nickel metal per liter, said excess hydrofluoric acid giving said bath a pH of more than 1 and less than 6, the anions of said bath comprising essentially fluorides and borates, said bath producing said highly ductile nickel coating ductile nickel coating on a metal base which is formed essentially from a nickel compound, hydrofluoric acid, boric acid and Water, said hydrofluoric acid reacting with said nickel compound to form a complex nickel fluoride, said hydrofluoric acid being present in a quantity in excess of that required to convert said nickel compound to said complex nickel fluoride, said bath containing at least 30 grams of nickel metal per
• hydrofluoric acid, boric acid and water said hy-- drofluoric acid reacting with said nickel compound to form a complex nickel fluoride, said' hydrofluoric acid being present in a quantity in excess of that required to convert said nickel compound to said complex nickel fluoride, said bath containing from 42 to grams of nickel metal per liter, said excess hydrofluoric acidgiving said bath a pH of more than 1 and less than 6, the anions of said bath comprising essentially fluorides and borates, said bath producing said highly ductile nickel coating when operated at current densities of less than 250 amperes per square decimeter.

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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)

Priority Applications (3)

Applications Claiming Priority (1)

Publications (1)

Family

ID=24727402

Family Applications (1)

Country Status (3)

Cited By (4)

Citations (1)

• 0
  • BE BE505404D patent/BE505404A/xx unknown
• 1946
  • 1946-06-26 US US679558A patent/US2576922A/en not_active Expired - Lifetime
• 1951
  • 1951-08-27 CH CH305430D patent/CH305430A/de unknown

Patent Citations (1)

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