Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
  • C23C28/40—Coatings including alternating layers following a pattern, a periodic or defined repetition
  • C23C28/44—Coatings including alternating layers following a pattern, a periodic or defined repetition characterized by a measurable physical property of the alternating layer or system, e.g. thickness, density, hardness
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
  • B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
  • B23K35/24—Selection of soldering or welding materials proper
  • B23K35/26—Selection of soldering or welding materials proper with the principal constituent melting at less than 400 degrees C
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
  • C23C28/02—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material
  • C23C28/021—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material including at least one metal alloy layer
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
  • C23C28/02—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material
  • C23C28/023—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D only coatings only including layers of metallic material only coatings of metal elements only
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C28/00—Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
  • C23C28/40—Coatings including alternating layers following a pattern, a periodic or defined repetition
  • C23C28/42—Coatings including alternating layers following a pattern, a periodic or defined repetition characterized by the composition of the alternating layers
• • 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
  • C25D5/10—Electroplating with more than one layer of the same or of different metals
  • C25D5/12—Electroplating with more than one layer of the same or of different metals at least one layer being of nickel or chromium
  • C25D5/14—Electroplating with more than one layer of the same or of different metals at least one layer being of nickel or chromium two or more layers being of nickel or chromium, e.g. duplex or triplex layers
• • 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
  • C25D5/60—Electroplating characterised by the structure or texture of the layers
  • C25D5/605—Surface topography of the layers, e.g. rough, dendritic or nodular layers
  • C25D5/611—Smooth layers
• • 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
  • C25D5/627—Electroplating characterised by the visual appearance of the layers, e.g. colour, brightness or mat appearance
• • 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
  • Y10S428/00—Stock material or miscellaneous articles
  • Y10S428/922—Static electricity metal bleed-off metallic stock
  • Y10S428/923—Physical dimension
  • Y10S428/924—Composite
  • Y10S428/926—Thickness of individual layer specified
• • 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
  • Y10S428/00—Stock material or miscellaneous articles
  • Y10S428/922—Static electricity metal bleed-off metallic stock
  • Y10S428/9265—Special properties
  • Y10S428/927—Decorative informative
• • 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
  • Y10S428/00—Stock material or miscellaneous articles
  • Y10S428/922—Static electricity metal bleed-off metallic stock
  • Y10S428/9335—Product by special process
  • Y10S428/934—Electrical process
  • Y10S428/935—Electroplating
• • 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
  • Y10S428/00—Stock material or miscellaneous articles
  • Y10S428/922—Static electricity metal bleed-off metallic stock
  • Y10S428/9335—Product by special process
  • Y10S428/936—Chemical deposition, e.g. electroless plating
• • 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.]
  • Y10T428/12701—Pb-base component
• • 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.]
  • Y10T428/12708—Sn-base component
• • 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.]
  • Y10T428/12771—Transition metal-base component
  • Y10T428/12778—Alternative base metals from diverse categories

Definitions

• the present invention relates to the provision of decorative and protective metallic coatings and, more particularly, to the provision on metallic surfaces of bright composite electrodeposited coatings which have substantially improved resistance to the destructive influences of industrial and marine atmospheres and which exhibit an attractive and decorative surface appearance for long periods of time during use.
• Electrodep'osited chromium is pleasing in appearance and offers a degree of resistance to corrosive atmospheres but fails to provide sufficient protection for underlying metals, e.g., ferrous metals, chiefly on account of the inherent porosity characterizing chromium electrodeposits. Electrodeposited nickel may also have a bright and pleasing appearance but nickel deposits on basis metals are characterized by fogging in industrial atmospheres and then by pitting at myriads of points on the surface.
• chromium reduces the fogging tendency of nickel but the chromium layer is thin and not impervious to atmospheric and other corrosive effects and, as a consequence thereof; exposure to atmospheres containing detrimental and corrosive substances, e.g., sulfur dioxide, leads to pitting and/or perforation of the composite coating.
• detrimental and corrosive substances e.g., sulfur dioxide
• pitting and/or perforation of the composite coating When these pits and/ or perforations penetrate through the coating to the basis metal, e.g., steel, the latter corrodes and unsightly corrosive products exude to the surface to mar its outward appearance.
• the protective value of conventional composite nickel-chromium coatings increases with increasing thickness of the nickel deposit, but commercially this has not proved to be a panacea for rust spotting of the plated metal, e.g., steel, exposed to weather.
• Another object of the invention is to provide metallic surfaces including metals and/or alloys with composite electrodeposited coatings characterized by a high degree of resistance to corrosion when subjected to weathering and which retain a decorative and pleasing surface appearance for relatively long periods of time during use.
• the invention also contemplates providing bright, decorative and protective composite electrodeposited coatings on metallic surfaces including metals and/0r alloys which, when compared to conventional composite coatings of comparable thickness, manifest an improved order of resistance to perforation by corrosive atmospheres, better protection of the metallic surface from corrosion and longer retention of a decorative and pleasing surface appearance during use.
• the invention further contemplates providing a process for accomplishing the foregoing objects.
• the composite electrodeposited coatings provided in accordance with the present invention are comprised of a plurality of electrodeposited nickel layers and a layer of electrodeposited dissimilar metal selected from the group consisting of cobalt, alloys of cobalt with up to 20% tungsten and up to nickel, tin, lead, silver and palladium interposed between said layers of nickel.
• Binary alloys of cobalt with about 10% to 20% tungsten and about 50% to 90% nickel may ad vantageously be employed in the interposed or intermediate layer.
• a relatively thin layer of chromium having a thickness of about 10 to 20 micro-inches is advantageously deposited on the outermost layer of nickel to contribute stain resistance to the composite coating.
• the composite coatings of the present invention are electrodeposited on a metallic base, including metals and/or alloys, it has been found that the coatings are more resistant to atmospheric and other corrosive eifects and retain a pleasing protective surface appearance longer during use than do known bright coatings of the same order of thickness, e.g., the conventional nickel-chromium and copper-nickel-chromium electrodeposits. It is important within the concepts of the present invention in order to insure the attainment of highly satisfactory results that the respective thicknesses of each of the electrodeposited metal layers comprising the composite coating be controlled with the following ranges:
• a basis nickel layer having a thickness of about 0.1 to 1 mil and an outer nickel layer having a thickness of about 0.1 to 2 mils are employed, superior results are obtained using a basis nickel layer having a thickness of about 0.1 to 1 mil and an outer nickel layer having a thickness of about 0.1 to 2 mils.
• thicker outer nickel layers should be employed when the basis nickel layer has a thickness in the lower portion of the range described.
• the outer nickel layer should be at least about 0.5 mil or, more advantageously, about 0.6 or 0.75 or 1 mil thick.
• the total thickness of nickel in the two layers should be at least about 0.5 mil but most advantageously is at least about 1 mil, particularly when the coating is to be subjected to outdoor exposure.
• the resulting coatings are superior in corrosion resistance to conventional nickel-chromium coatings having the same thickness of nickel, and it is thus advantageous to use these metals for the intermediate layer to obtain the most satisfactory results.
• composite coatings within the invention are superior for decorative and protective purposes to conventional nickel-chromium coatings having twice the thickness of nickel.
• the efiectiveness of composite coatings having an interposed layer of cobalt or a cobalt-containing alloy increases as the thickness of the intermediate layer is increased up to'.l mil.
• the nickel layers contemplated by the invention may be made of electrodeposited nickel obtained from plating baths of the conventional Watts type, or may be made of bright or semi-bright nickel deposited from baths containing the usual brighteners and/or levelers for enhancing the smoothness and appearance of the nickel electrodeposit.
• Nickel plating baths for producing nickel deposits satisfactory for use in the present invention contain up to 400 grams per liter of nickel sulfate (NiSO .7H O), up to 400 grams per liter of nickel chloride (NiCl 6H O) and up to 50 grams per liter (preferably 10 to 40 grams per liter) of a buffer such as boric acid.
• the essential ingredients of the Wattstype nickel plating bath are nickel sulfate (NiSO -7H O) and nickel chloride (NiCl -6H O) which may be present in the bath in amounts of about to about 400 grams per liter and of about 10 to about 60 grams per liter, respectively.
• the bath is operated in the pH range of about 1.5 to 6.
• a buffering agent such as boric acid is included in the bath in an amount of up to about 50 grams per liter, e.g., about 10 to about 40 grams of boric acid per liter.
• a small amount (e.g., about 0.2 gram per liter) of a wetting agent such as a sodium lauryl sulfate is usually included in the bath to prevent undesirable pitting.
• Cathode current densities of about 20 to about 100 amperes per square foot are usually employed and the operating range of bath temperatures is about to about 160 F.
• Nickel deposited from the Watts-type bath generally will require bufiing before application of the final chromium plate to insure a fully bright appearance.
• Plating baths for plating bright nickel are of generally similar composition to the Watts-type bath and may, for example, contain about 25 to 300 grams per liter of nickel sulfate (NiSO -7H O) and 30 to 225 grams per liter of nickel chloride (NiCl -6H O), with up to 50 grams per liter of boric acid as a buffer.
• Bright nickel baths include combinations of addition agents for producing a more lustrous and brighter deposit than is obtainable with the Watts-type bath. These addition agents generally include a combination of a wetting agent, a leveling and/or smoothing agent, a luster-producing agent and a stressreducing agent.
• Bright nickel plating baths are discussed in Modern Electroplating, John Wiley and Sons, Inc., New York, 1953, at pages 311 to 318, and in many US. patents, including, e.g., Patents Nos. 2,191,813, 2,389,135, 2,524,619, 2,647,866 and 2,648,628.
• Plating baths for producing semi-bright nickel are generally similar in composition to Watts-type baths and bright nickel baths and contain a leveling agent, such as coumarin and derivatives thereof, which contributes a leveling and scratch-covering property to the plate without introducing a high level of stress therein as may be the case with bright nickel.
• Semi-bright nickel plates are not as bright as the bright nickel plates but are more easily buffed than conventional Watts-type plates and are characterized by a high degree of smoothness.
• Nickel electrodeposits from the Watts-type bath generally have a hardness of about to Vickers, while bright nickel electrodeposits generally have a higher hardness which may be as high as about 500 Vickers.
• a particular embodiment of the invention wherein a satisfactory composite coating upon an underlying metal, e.g., steel, is provided without any mechanical polishing operation, e.g., bufling, includes the following steps: (1) prepare the underlying metal for plating, (2) deposit a layer of gray or Watts-type nickel thereon in a thickness as hereinbefore described, (3) deposit an intermediate layer of metal of the hereinbefore-described kind and thickness, (4) deposit a bright outer nickel layer of the hereinbefore-described thickness and (S) deposit an outer chromium layer over the said bright nickel layer.
• the aforedcscribed outer nickel layer may advantageously comprise a layer of semi-bright nickel applied over the intermediate layer in sufiicient thickness to provide a good leveling action, e.g., about 0.5 mil, and a layer thereover of bright nickel to provide a bright finish upon which the final chromium layer may be applied.
• layers of bright nickel may be employed in accordance with the invention.
• the invention also contemplates multi-layer coatings having a plurality of electrodeposited intermediate layers of the kind and thickness described hereinbefore and having a plurality of electrodeposited nickel layers having thicknesses as aforedescribed.
• a multilayer composite on steel comprising a layer on the steel of electrodeposited nickel 0.1 mil thick, a layer thereon of electrodeposited cobalt 0.1 mil thick, another layer of nickel 0.1 mil thick, a further layer of cobalt 0.1 mil thick, and an outer layer of nickel 1 mil thick, with a decorative coating of chromium IO-micro-inches thick is a satisfactory multi-layer composite in accordance with the invention.
• test specimens for the most part were electrodeposited upon panels of polished SAE 1010 steel in the form of /s x 4 x 6 plates.
• One of the sets of test specimens comprised foils which were made by electrodepositing coatings to be tested on a highly polished cobalt-chromium alloy (such as is sold under the trademark Stellite) starting sheet from which electrodeposited foils could easily be stripped.
• Conventional cleaning and plating methods well known to those skilled in the art were employed in the preparation of the test panels and foils.
• the steel panels were prepared for plating according to the following procedure.
• the panels were examined to compare the corrosion resistance of the coatings deposited thereon with each other and with the nickel-chromium control panels of the conventional type.
• the examination comprised a visual inspection wherein the panels were given a merit rating designating the relative order and the appearance of each panel, with the panel exhibiting the best appearance being designated by the numeral 1.
• the panels were rated according to the method recommended by the American Society for Testing Materials Committee B8, Subcommittee II, described in the Proceedings of the A.S.T.M., vol. 49 (1949), at pages 220 et seq. This method involves examination of the test panels to determine the corrosion-affected area and comparing the panels with standards so that a rating number up to 10 could be assigned thereto.
• This set included 1 mil thick composite electrodeposited coatings of the sandwich type including 0.1 mil thick intermediate layers of a cobalt-tungsten alloy containing about 15% tungsten, cobalt, tin, lead, palladium, silver and copper. Panels containing intermediate 0.3 mil thick layers of tin (panel 28) and of lead (panel 31) were also included. A panel having the conventional nickel-chromium electrodeposited coating of the same 1 mil thickness was also included (panel 35). Examination of these panels showed that all of the composite coatings within the invention were superior in corrosion resistance to the conventional nickel-chromium electrodeposit.
• the composites containing the thicker (0.05 and 0.1 mil) cobalt intermediate layers were rated as good as, or better than, the conventional nickelchromium control panels, even those having twice the nickel thickness. It was noted that the composites containing an intermediate layer of tin were prone to develop white stain spots, especially as the thickness of the tin intermediate layer was increased.
• Panel 55 the 1.5 mil thick composite coating, was rated best on the basis of appearance and protective value even as against panel 61, the conventional 2 mil thick coating.
• the blistering tendency of the composites containing the cobalt intermediate layer caused them to be rated low according to the A.S.T.M. system.
• the composite coatings containing the tin intermediate layers as thin as 0.025 mil demonstrated an improved protactive effect as compared to the conventional nickel-chromium control panels.
• Ni-Co-Ni. .49 01 .5 9 8.5 Ni-CoNi-N 4 1 5 8 4 .4-.1-.5 1 5.1 Nickel 1.0 5 O .4.1-.5 2 6 -do 2.0 9 7 .4-.1.5 3 8.9 3.0 9 8 2. 3. 4 4-.1-. 5 5 6. 8 4-. 1. 5 6 3. 9 2-. 3. 5 7 5.05 ti"? 3 3'1 .4-.1-.5 10 2.1 Table VII COMPOSITE COATED STEEL PANELS MADE USING WATTS 1 Visual rating in order oi merit with N o. 1 best.
• Brightening agent a mixture of saccharin, benzene sulfonamide and paratoluene sulfonamide
• Luster-producing agent containing pyrodininm and quinolinium compounds 1.25 ml./l.
• Wetting agent a mixture of agents exemplified by a sodium salt of lauryl sulfoacetate and a sodium salt of monolauryl ether of ethylene glycol monosulfate 5 ml./l.
• silver strike was ,first applied Silver strike solution AgCN 5 gpl Ag 4 gpl NaCN gpl Silver strike conditions Temperature 76 F. Current density 20 a.s.f.
• Plating composition Lead 32 oz./gal. Lead fiuoborate 59 oz./ gal. Boric acid 3.8 oZ./gal. Hydrofluoric acid (free) 5.4 0z./gal. Plating conditions- Temperature 76 F. Current density 16.5 a.s.f. Anodes Chemical lead.
• the outer nickel layer was deposited on the layer 13 of lead, the latter was subjected to the following pretreatment: '(1) water rinsed, (2) anodically treated in alkaline solution for 15 seconds at 6 volts and at a temperature of 76 F.
• the solution contained 50 g.p.l. of NaOAc.
• the present invention is particularly applicable to providing composite electrodeposited coatings on structural metals which are susceptible to atmospheric attack when exposed by themselves.
• foundation metals are copper, zinc, aluminum, brass, etc., and alloys such as steel, e.g., carbon steels and low alloy steels containing phases associated with alpha iron, etc.
• the composite electrodeposits of the invention are suitable for use in both industrial and marine atmospheres.
• the beneficial effects brought about by the invention are not explainable on the simple basis of interrupting the continuity of the nickel coating, although this factor is involved.
• the available data indicate that the kind of metal used in the intermediate layer and the thickness of the intermediate layer are of primary importance in carrying out the invention to produce protective and decorative electrodeposited coatings having a thickness of about 1 mil, e.g., at least about 0.25 mil to 3 or 4 mils.
• the data also indicate that the metals cobalt, alloys thereof with tungsten and nickel, lead, tin, silver and palladium meet the requirements for producing improved results in composite electrodeposited decorative and protective coatings in accordance with the invention.
• Metal coatings e.g., nickel coatings, for use in accordance with the invention advantageously are produced by electrodeposition.
• chemically deposited nickel coatings and cobalt coatings such as those described in the Brenner et al U.S. Patents Nos. 2,532,283 and 2,532,284, coatings produced by high vacuum vaporizing and by thermal decomposition of metal carbonyls, such as nickel carbonyl, may also be employed to produce metal layers in accordance with the invention.
• a metal article having firmly bonded to the surface thereof a protective and decorative composite metal coating, said coating consisting of a foundation layer of nickel about 0.1 to about 2 mils thick deposited on said metal surface, an electro- 14 deposited metal layer of cobalt with up to 20% tungsten and up to nickel about 0.01 mil to about 0.3 mil thick applied to said nickel layer, a layer of nickel about 0.5 to 2 mils thick applied to said metal layer, and an outer decorative layer of electrodeposited chromium, said composite coating being characterized by an improved decorative and protective effect as compared to a coating having a single nickel layer of the same thickness.
• a metal article having firmly bonded to the surface thereof a protective and decorative composite metal coating, said coating consisting of a foundation layer of nickel about 0.1 to about 2 mils'thick deposited on said metal surface, an electrodeposited cobalt layer about 0.01 to about 0.1 mil thick applied to'said nickel layer, a layer of nickel about 0.5 to '2 mils thick applied to said cobalt layer, and an outer decorative layer of electrodeposited chromium, said composite coating being characterized by an improved decorative and protective eifect as compared to a coating having a single nickel layer of the same thickness.
• a metal article having firmly bonded to the surface thereof a protective and decorative composite metal coating, said coating consisting of a foundation layer of nickel about 0.1 to about 2 mils thick deposited on said metal surface, a layer of electrodeposited dissimilar metal about 0.01 mil to about 0.3 mil thick from the group consisting of tin, lead, silver, palladium, cobalt and alloys of cobalt with up to 20% tungsten and up to 90% nickel applied to said nickel layer, a layer of nickel about 0.5 to 2 mils thick applied to said dissimilar metal layer, and an outer decorative layer of electrodeposited chromium, said composite coating being at least about 0.25 mil thick and being characterized by an improved decorative and protective efiect in the deposited condition as compared to a coating having a single nickel layer of the same thickness.
• a metal article having firmly bonded to the surface thereof a protective and decorative composite metal coating at least about 1 mil and up to about 4 mils thick, said coating consisting of a plurality of electrodeposited nickel layers wherein the outermost nickel layer is about 0.1 to 2 mils thick and at least one intermediate layer of electrodeposited dissimilar metal from the group consisting of tin about 0.05 to about 0.3 mil thick, lead about 0.1 to about 0.3 mil thick, silver about 0:05 to about 0.2 mil thick, palladium about 0.05 to about 0.2 mil thick, cobalt about 0.01 to about 0.1 mil thick, an alloy of cobalt with up to 20% tungsten about 0.05 to about 0.2 mil thick and an alloy of cobalt with up to 90% nickel about 0.1 to about 0.3 mil thick adherently contacting two of said nickel layers, said composite coating being characterized by an improved protective and decorative effect in the deposited condition as compared to a coating having a single nickel layer of the same thickness.
• the improvement which consists of depositing a nickel layer about 0.1 to 2 mils thick upon a metal article, electrodepositing a dissimilar metal layer from the group consisting of tin about 0.05 to about 0.3 mil thick, lead about 0.1 to about 0.3 mil thick, silver about 0.05 to about 0.2 mil thick, palladium about 0.05 to about 0.2 mil thick, cobalt about 0.01 to.
• improvement which consists of depositing a nickel layer about 0.1 to about 2 mils thick upon said article, electrodepositing upon said nickel layer a layer of dissimilar metal about 0.01 to about 0.3 mil thick from the group consisting of tin, lead, silver, palladium, cobalt and alloys of cobalt with up to 20% tungsten and up to 90% nickel, depositing a nickel layer about 0.5 to about 2 mils thick upon said dissimilar metal layer and depositing an outer chromium layer about to 20 micro-inches thick upon the composite coating to provide a coated metal article having a composite protective and decorative coating characterized by an improved decorative and protective etfect as compared to a similar coated article having a single nickel layer of the same total nickel thickness.
• the improvement which consists of depositing a nickel layer about 0.1 mil to about 2 mils thick upon said article, electrodepositing upon said nickel layer an intermediate layer about 0.01 to about 0.3 mil thick of cobalt with up to 20% tungsten and up to 90% nickel, depositing on said intermediate layer a nickel layer about 0.5 to about 2 mils thick, depositing an outer chromium layer to provide a decorative and protective composite coating characterized by an improved decorative and protective effect in the deposited condition as compared to a coating having a single nickel layer of the same total nickel thickness.
• the improvement which consists of depositing a nickel layer about 0.1 to 2 mils thick upon a metal article, electrodepositing a cobalt layer about 0.01 to about 0.1 mil thick upon said nickel layer, depositing a nickel layer about 0.5 to about 2 mils thickupon said cobalt layer and depositing an outer chromium layer about 10 to 20 microinches thick to provide a coated metal article having a composite protective and decorative coating characterized by an improved efiect as compared to a similar metal ar- 16 ticle having thereon a single nickel layer of the same total thickness.
• a metal article having firmly bonded to the surface thereof a composite metal coating at least about 1 mil and up to about 4 mils thick, said coating consisting of a plurality of electrodeposited nickel layers wherein the outermost nickel layer is about 0.1 to 2 mils thick, and at least one electrodeposited intermediate layer about 0.05 to about 0.2 mil thick of a cobalt-tungsten alloy containing about 10% to 20% tungsten and the balance essentially cobalt adherently contacting two of said nickel layers, said composite coating being characterized by an improved protective effect in the deposited condition as compared to a coating having a single nickel layer of the same total thickness.
• a metal article having firmly bonded to the surface thereof a composite metal coating at least about 1 mil and up to about 4 mils thick, said coating consisting of a plurality of electrodeposited nickel layers .wherein the outermost nickel layer is about 0.1 to 2 mils thick, and at least one electrodeposited intermediate layer about 0.1 mil to about 0.3 mil thick of a cobalt-nickel alloy containing about to nickel with the balance essentially cobalt adherently contacting two of said nickel layers, said composite coating being characterized by an improved protective effect in the deposited condition as compared to a coating having a single nickel layer of the same total thickness.

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• 0
  • NL NL111001D patent/NL111001C/xx active
• 1957
  • 1957-12-03 US US700263A patent/US3009238A/en not_active Expired - Lifetime
• 1958
  • 1958-11-27 GB GB38325/58A patent/GB853236A/en not_active Expired
  • 1958-11-28 SE SE1105758A patent/SE205363C1/sv unknown
  • 1958-12-01 DE DEM39805A patent/DE1177451B/de active Pending
  • 1958-12-03 CH CH6693958A patent/CH385588A/fr unknown
• 1959
  • 1959-10-15 BE BE583670A patent/BE583670A/fr unknown

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