Classifications

• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D1/00—Electroforming
  • C25D1/08—Perforated or foraminous objects, e.g. sieves
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
  • B22F3/10—Sintering only
  • B22F3/11—Making porous workpieces or articles
  • B22F3/1121—Making porous workpieces or articles by using decomposable, meltable or sublimatable fillers
  • B22F3/1137—Making porous workpieces or articles by using decomposable, meltable or sublimatable fillers by coating porous removable preforms
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C1/00—Making non-ferrous alloys
  • C22C1/08—Alloys with open or closed pores
• • 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
  • C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
  • C23C18/16—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by reduction or substitution, e.g. electroless plating
  • C23C18/31—Coating with metals
• • 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
  • C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
  • C23C18/16—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by reduction or substitution, e.g. electroless plating
  • C23C18/31—Coating with metals
  • C23C18/42—Coating with noble metals
  • C23C18/44—Coating with noble metals using reducing agents
• • 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
  • C25D3/46—Electroplating: Baths therefor from solutions of silver
• • 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
  • C25D5/02—Electroplating of selected surface areas
  • C25D5/022—Electroplating of selected surface areas using masking means
• • 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
  • C25D5/48—After-treatment of electroplated surfaces
  • C25D5/50—After-treatment of electroplated surfaces by heat-treatment
• • 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
  • C25D5/54—Electroplating of non-metallic surfaces
  • C25D5/56—Electroplating of non-metallic surfaces of plastics
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R43/00—Apparatus or processes specially adapted for manufacturing, assembling, maintaining, or repairing of line connectors or current collectors or for joining electric conductors
  • H01R43/007—Apparatus or processes specially adapted for manufacturing, assembling, maintaining, or repairing of line connectors or current collectors or for joining electric conductors for elastomeric connecting elements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/64—Carriers or collectors
  • H01M4/70—Carriers or collectors characterised by shape or form
  • H01M4/80—Porous plates, e.g. sintered carriers
  • H01M4/808—Foamed, spongy materials
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R13/00—Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
  • H01R13/02—Contact members
  • H01R13/03—Contact members characterised by the material, e.g. plating, or coating materials
• • 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
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries

Definitions

• the present invention relates to a method for manufacturing metal foam that can be used as a contact device in electrical connections as well as in numerous applications for which the mechanical characteristics, electrical conduction or thermal conduction of such a foam are used. .
• the metal foam and in particular the silver foam used as contact in the electrical connections is described in the PCT patent application WO 2004/049515.
• the plate-shaped metal foam is interposed between the two contact surfaces of an electrical connection.
• the foam increases the points of contact between the two contact surfaces and thus allows a homogeneous distribution of the current.
• the use of the foam is even more advantageous in the case where the electrical connection is degraded and deformed insofar as it significantly increases the electrical conductance of the connection which has degraded due to the formation of oxides.
• the metal foam plates are generally obtained by electrolysis.
• the electrically conductive foam sheet is used as a cathode in an electrolytic bath so as to cover all the surfaces with a layer of metal.
• European Patent EP 1,356,137 describes two methods for making the foam conductive, generally polyurethane or equivalent.
• the first method is to deposit on the foam a monomer such as pyrrole whose polymer form is electrically conductive. It is therefore necessary to proceed to the polymerization step.
• the second method is to deposit the metal, copper in this case, by the technique of vacuum deposition. This method which is carried out at high temperature unfortunately requires significant technical means.
• These two methods have a major disadvantage. Indeed, they do not allow an equal deposition, either monomer or copper, on all surfaces of the cells of the foam.
• patent EP 1.356.137 mainly describes the method of removing the organic foam to keep only the copper foam, by the use of an oven whose atmosphere is composed of water vapor. This technique performed in the absence of oxygen is intended to prevent the oxidation of copper, which would otherwise become brittle.
• the object of the invention is to provide a method of manufacturing a metal foam such as silver or gold in which the polyurethane foam is made electrically conductive by the deposition of metal. simply using a chemical bath.
• Another object of the invention is to provide a process for manufacturing a metal foam such as silver or gold in which the removal of the polymer used to support the foam is carried out by simply burning the foam. foam after the electrolysis step.
• Yet another object of the invention is to provide a metal foam such as silver or gold that can be used in many applications that take advantage of the mechanical characteristics, electrical conduction or thermal conduction of the foam.
• the object of the invention is therefore a method of manufacturing metal foam such as silver or gold consisting of depositing chemically a first layer of thin metal on the surface of the cells of a foam of polyurethane or equivalent to obtain a metal foam and to electrolytically deposit a second layer of the same metal of much greater thickness on the surface of the cells of said metal foam.
• Another aspect of the invention is the metal foam obtained by the above process as well as the many possible applications due to the combination of the characteristics specific to the structure of the foam on the one hand and the characteristics specific to the metal of somewhere else
• the preferred embodiment described in the following description relates to the method of manufacturing the silver foam. But other embodiments relating to metals other than silver, can be implemented by adapting the manufacturing process.
• open-cell polyurethane foam boards having a spongy consistency are used so that they can be used, after their transformation into silver foam, in many applications and in particular for the contacts of electrical connections.
• the polyurethane foam sheets have a thickness of between 1 mm and 2 mm and are in the form of rectangles whose dimensions are between 10 cm and 40 cm. However, larger plates, in the form of rolls, could also be used.
• the method of obtaining the silver foam plates consists of two essential steps. The first step is a step of activating the foam by chemical deposition of a small silver layer and the second step is an electrolysis step during which a thick silver layer is deposited by electrolysis.
• the activation step is subdivided into following steps
• Step proper activation which is subdivided itself in several steps: a) is prepared a silver nitrate silver bath (assayed for example 120 g / 1) in a deionized water bath containing ammonia and potash. b) Pour a reducer into the silver bath. This reducing agent is preferably glucose, for example at 92 g / l; but it could be formalin. c) Immediately after pouring the reducer into the silver bath, the new bath obtained is poured onto the foam plates in a treatment tank.
• a soda solution for example sodium hydroxide solution
• the second essential step is to deposit silver on all the surfaces of the cells of the silver foam. It is divided into several stages: 1. Preparation of an electrolysis bath composed of silver cyanide, for example at 35 g / l in deionized water containing potassium carbonate.
• Electrolysis by producing a current of 30 A between the silver anodes connected to the positive terminal and the silver foam plates connected to the negative terminal.
• the electrolysis is carried out for a quarter of an hour.
• silver foam plates with a thickness of 1 mm contain about 500 g of silver per m 2 .
• the silver foam thus obtained is thus composed of a silver-covered polyurethane skeleton which gives it the properties which have been described in PCT patent application WO 2004/049515.
• an additional step makes it possible to obtain a pure silver foam by discarding the polyurethane skeleton. This step involves igniting one end of the plate. Polyurethane, fuel, burns. The flame is spreading from one end of the plate to the other. Ultimately, all the polyurethane was burned when the flame extinguished, leaving a foam entirely formed of silver which reveals improved properties when used as contact in particular according to the teachings of the PCT patent application WO 2004 / 049515.
• the silver has been used in the manufacturing process just described because silver has the best electrical conductivity of all metals, which is a considerable advantage for the application of foam. money in improving the contacts in the electrical connections.
• the silver also has the best thermal conductivity, which allows a good evacuation of the heat produced in the connections where the silver foam is used.
• Another advantage of silver is its unalterable character in the presence of oxygen which, as just saw, eliminates the skeleton of polyurethane foam without using a heavy method away from the air.
• the metal foams made by the process according to the invention can be used in many applications because of the combination of their characteristics specific to the foam structure on the one hand and their characteristics specific to the metal on the other hand.
• metal foams can be favorably used as battery electrodes (copper, nickel) and as electrodes for chlorine / sodium electrolysis (titanium, nickel).
• metal foam as a technical seal (for example filtering sealing for aviation) with very high temperature holdings for silver in particular, while maintaining a satisfactory electrical conductivity ( unlike most sealants).
• metal foams as very fine filters that can be used at any temperature can be considered since Such filters will have the same filtering properties obtained with polyurethane foams and will have good resistance to high temperature which is obviously not the case of polyurethane foam filters.
• Metal foams can be integrated into composite materials with not only significant electrical but also mechanical and tribological capabilities.
• the heat transfer capacity of the metal foams due to their thermal conductivity should allow them to be used in the surfaces of the heat exchangers.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Metallurgy (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Mechanical Engineering (AREA)
• General Chemical & Material Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
• Cell Electrode Carriers And Collectors (AREA)
• Chemically Coating (AREA)
• Laminated Bodies (AREA)

Applications Claiming Priority (2)

Publications (1)

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• 2006
  • 2006-04-20 WO PCT/IB2006/000942 patent/WO2006111837A2/fr not_active Ceased
  • 2006-04-20 EP EP06727513A patent/EP1963548A2/de not_active Withdrawn

Non-Patent Citations (1)

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