EP0624206B1 - Leitfähiges material mit hoher härte und verfahren zu seiner herstellung - Google Patents

Leitfähiges material mit hoher härte und verfahren zu seiner herstellung Download PDF

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Publication number
EP0624206B1
EP0624206B1 EP93904133A EP93904133A EP0624206B1 EP 0624206 B1 EP0624206 B1 EP 0624206B1 EP 93904133 A EP93904133 A EP 93904133A EP 93904133 A EP93904133 A EP 93904133A EP 0624206 B1 EP0624206 B1 EP 0624206B1
Authority
EP
European Patent Office
Prior art keywords
conductive material
material according
oxide
hardness conductive
alloy
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP93904133A
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English (en)
French (fr)
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EP0624206A1 (de
Inventor
Christian Bataillon
Solange Brunet
Odette Sanatine
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
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Commissariat a lEnergie Atomique CEA
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Publication of EP0624206A1 publication Critical patent/EP0624206A1/de
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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/06—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances
    • H01B1/08—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances oxides
    • 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
    • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
    • C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
    • C23C8/10—Oxidising

Definitions

  • the present invention relates to a conductive material of high hardness and its manufacturing process.
  • connection elements or the relay contacts In the field of electrical contacts used in connectors, in mobile relays, etc., we have long sought to make contacts which, owing to their hardness, are capable of operating for a very long time even under difficult conditions.
  • the materials used to make these connection elements or the relay contacts must have very good physical and chemical unalterability properties, great hardness and of course good electronic conductivity properties.
  • the object of the invention is to remedy these drawbacks and to produce a material of high hardness, of great chemical inertness and of good electronic conductivity, which can be used for example as an electrical contact.
  • the invention relates to a conductive material of high hardness.
  • this material consists of an alloy comprising a first oxide of a metal, this first insulating and unalterable oxide forming the matrix of the material and a second oxide of an addition element forming a conductor electronic, the various islands constituting this second oxide being interconnected to form a conductive path inside said matrix.
  • the metal is chosen from the elements of groups IVb or Vb of the periodic table, for example titanium, zirconium or niobium.
  • the addition element is chosen from the elements of groups Ib, IIb, IIIa or IVa of the periodic table, for example copper, silver, mercury, indium or tin.
  • the oxidation stage makes it possible, on the one hand, to make the base metal unalterable and, on the other hand, to form precipitates or islets which conduct the addition element oxide inside the oxide. base metal. Then, the physical percolation treatment makes it possible to interconnect the conductive islands produced by oxidation and thus ensure the electronic conductivity of the material obtained.
  • the oxidation of the alloy is carried out either by anodization when the alloy is in the form of a thin film, with a thickness of less than 0.5 ⁇ m, or by the action of a gaseous oxidant. , liquid or dissolved, at a temperature close to 400 ° C, when the alloy is in the form of a thick film.
  • the physical percolation treatment is carried out by a heat treatment at a temperature below the phase transition temperature of the alloy considered.
  • the material according to the invention is an alloy comprising a first oxide of a metal, this first insulating and unalterable oxide forming the matrix of the material and a second oxide of an addition element forming an electronic conductor, the various islands constituting this second oxide being interconnected to form a conductive path inside said matrix.
  • the metal whose oxide is insulating but which resists physical attacks relatively well and chemical is chosen from the elements of groups IVb or Vb of the periodic table.
  • titanium, zirconium and niobium are preferred but nonlimiting examples.
  • the addition element is chosen from the metals of groups lb, IIb, IIIa or IVa of the periodic table.
  • these metals copper, silver, mercury, indium and tin are particularly well suited. However, these are not the only conductive oxides that can be used.
  • the zirconium couple associated with a small percentage of tin gives good results.
  • the maximum concentration of additive element corresponds to the limit of solubility in the metal matrix. Not all of these solubility limits are known, however, those of tin in zirconium are known. This is 17 atomic%.
  • the minimum concentration of addition elements in the alloy is that corresponding to the proportion sufficient for a percolation phenomenon to occur later in the final step. This concentration is approximately 0.1 atomic%.
  • This method comprises a first step consisting in taking or preparing an alloy comprising a metal whose oxide is unalterable and insulating and an addition element whose oxide is an electronic conductor with the metals and elements previously described.
  • the next step in the process according to the invention consists in subjecting this alloy to oxidation.
  • This oxidation makes the base metal unalterable since already oxidized and creates conductive precipitates in the oxide matrix.
  • the oxidation can be carried out, for example, by anodization, by dry oxidation or by the action of a gaseous, liquid or dissolved oxidant, the latter possibly being water or water vapor.
  • Oxidation can be carried out either in massive form, or in the form of a coating deposited directly on a metal part in order to give it the desired properties of inalterability and electronic conductivity.
  • the implementation of the method according to the invention must meet two main objectives, on the one hand, to allow the rapid production of films of conductive material of high hardness and on the other hand, to obtain compact films, that is to say - say without mechanical defects such as pores or cracks.
  • the faster an oxidation and the less compact the film obtained It is therefore necessary to find a compromise between the mechanical quality of the film and its speed of manufacture.
  • anodization is the most suitable oxidation mode.
  • oxidation in water vapor at around 400 ° C. gives very good results, with a speed oxidation of 1 to 2 ⁇ m per week.
  • the third step of the manufacturing process according to the invention consists in subjecting the oxidized alloy to physical treatment in order to create, by a percolation phenomenon, conductive paths interconnected in the insulating oxide layer.
  • Percolation is a physical phenomenon that allows certain transfers to take place in a solid. When this percolation treatment is carried out, the electric charges can pass by following particular paths within the non-conductive oxide.
  • the percolation treatment is described for example in a book entitled "Introduction to percolation theory", (Introduction to the theory of percolation), Stauffer D., Aharony A., London: Taylor and Francis, 1992.
  • the oxidation step made it possible to produce precipitates or islets of conductive oxide which are linked together by this percolation treatment.
  • This percolation treatment is generally carried out by a heat treatment. Its role is to create the necessary connections, if the nature and concentration of the constituents allow it. The concentration ranges have been given beforehand.
  • the structure of the alloy must remain the same as at normal temperature of use. It is therefore necessary to operate at a temperature lower than that where a phase change begins to occur (phase transition temperature). This temperature naturally depends on the material considered.
  • This physical treatment can be carried out by a global heat treatment or on the contrary by a local heat treatment, intended to make conductive only a limited surface of the part considered. In the latter case, only part of the part is conductive and one can benefit from the insulating properties on the rest of the surface thereof.
  • Zirconium and tin alloys known under the trade name ZIRCALOY 2 and ZIRCALOY 4 were oxidized at 400 ° C in water vapor, placing them in an autoclave suitable for this type of operation. The oxidation lasted 1 to 2 weeks depending on the thickness desired for the oxide film. Then, the oxidized material was placed in an oven under primary vacuum, then heated for 1 to 2 hours at a temperature between 400 and 600 ° C to make the oxide layer conductive. Then, the material was rapidly cooled by introducing an inert gas such as argon or helium into the furnace.
  • an inert gas such as argon or helium

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Conductive Materials (AREA)

Claims (18)

  1. Leitfähiges Material mit hoher Härte dadurch gekennzeichnet, daß es gebildet wird durch eine Legierung, umfassend ein erstes Oxid eines Metalls, wobei dieses erste isolierende und beständige Oxid die metallische Matrix des Materials bildet, und ein zweites Oxid eines Legierungselements, einen elektronischen Leiter bildend, wobei die verschiedenen, dieses zweite Oxid bildenden Inseln miteinander verbunden sind, um im Innern der besagten Matrix einen leitfähigen Weg bzw. Pfad zu bilden.
  2. Leitfähiges Material hoher Härte nach Anspruch 1, dadurch gekennzeichnet, daß das Metall ausgewählt wird unter den Elementen der Gruppen IVb oder Vb des Periodensystems.
  3. Leitfähiges Material hoher Härte nach Anspruch 1, dadurch gekennzeichnet, daß das Legierungselement ausgewählt wird unter den Elementen der Gruppen Ib, IIb, IIIa oder IVa des Periodensystems.
  4. Leitfähiges Material hoher Härte nach Anspruch 2, dadurch gekennzeichnet, daß das Metall ausgewählt wird unter Titan, Zirkon und Niobium.
  5. Leitfähiges Material hoher Härte nach Anspruch 3, dadurch gekennzeichnet, daß das Legierungselement ausgewählt wird unter Kupfer, Silber, Quecksilber, Indium oder Zinn.
  6. Leitfähiges Material hoher Härte nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß das erste Oxid ein Zirkonoxid ist, und daß das zweite Oxid ein Zinnoxid ist.
  7. Leitfähiges Material hoher Härte nach einem der vorangehenden Ansprüche, dadurch gekennzeichnet, daß die Legierungselement-Konzentration in der Legierung enthalten ist zwischen 0,1% Atomanteil und dem ihrer Lösbarkeitsgrenze in der metallischen Matrix entsprechenden Wert.
  8. Herstellungsverfahren eines leitfähigen Materials hoher Härte nach einem der Ansprüche 1 bis 7, dadurch gekennzeichnet, daß es die folgenden Schritte umfaßt:
    - Wählen einer Legierung, die ein Metall enthält, dessen Oxid beständig und isolierend ist, und ein Legierungselement, dessen Oxid ein elektronischer Leiter ist,
    - Oxidieren dieser Legierung, und
    - Durchführen einer physikalischen Behandlung dieser oxidierten Legierung, um durch ein Perkolationsphänomen in der Oxidschicht miteinander verbundene leitfähige Pfade zu erzeugen.
  9. Herstellungsverfahren eines leitfähigen Materials hoher Härte nach Anspruch 8, dadurch gekennzeichnet, daß das Metall, dessen Oxid isolierend ist, ausgewählt wird unter den Elementen der Gruppen IVb oder Vb des Periodensystems.
  10. Herstellungsverfahren eines leitfähigen Materials hoher Härte nach Anspruch 9, dadurch gekennzeichnet, daß das Metall ausgewählt wird unter Titan, Zirkon oder Niobium.
  11. Herstellungsverfahren eines leitfähigen Materials hoher Härte nach Anspruch 8, dadurch gekennzeichnet, daß das Legierungselement ausgewählt wird unter den Elementen der Gruppen Ib, IIb, IIIa oder IVa des Periodensystems.
  12. Herstellungsverfahren eines leitfähigen Materials hoher Härte nach Anspruch 11, dadurch gekennzeichnet, daß das Legierungselement ausgewählt wird unter Kupfer, Silber, Quecksilber, Indium oder Zinn.
  13. Herstellungsverfahren eines leitfähigen Materials hoher Härte nach einem der Ansprüche 8 bis 12, dadurch gekennzeichnet, daß die Legierungselement-Konzentration in der Legierung enthalten ist zwischen 0,1% Atomanteil und dem ihrer Lösbarkeitsgrenze in der metallischen Matrix entsprechenden Wert.
  14. Herstellungsverfahren eines leitfähigen Materials hoher Härte nach einem der Ansprüche 8 bis 13, dadurch gekennzeichnet, daß die Legierung in Form eines dünnen Films mit einer Dicke unter 0,5 µm verwendet wird.
  15. Herstellungsverfahren eines leitfähigen Materials hoher Härte nach Anspruch 14, dadurch gekennzeichnet, daß die Oxidation der Legierung durch Anodisation erfolgt.
  16. Herstellungsverfahren eines leitfähigen Materials hoher Härte nach einem der Ansprüche 8 bis 13, dadurch gekennzeichnet, daß die Legierung in Form eines dicken Films mit einer Dicke über 0,5 µm verwendet wird.
  17. Herstellungsverfahren eines leitfähigen Materials hoher Härte nach Anspruch 16, dadurch gekennzeichnet, daß die Oxidation der Legierung unter der Wirkung eines gasförmigen, flüssigen oder gelösten Oxidierungsmittels erfolgt, bei einer Temperatur um 400°C.
  18. Herstellungsverfahren eines leitfähigen Materials hoher Härte nach Anspruch 13, dadurch gekennzeichnet, daß die die Perkolation bewirkende physikalische Behandlung eine Wärmebehandlung ist, durchgeführt bei einer niedrigeren Temperatur als der Phasenübergangstemperatur der betreffenden Legierung.
EP93904133A 1992-01-30 1993-01-28 Leitfähiges material mit hoher härte und verfahren zu seiner herstellung Expired - Lifetime EP0624206B1 (de)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR9201026A FR2686903B1 (fr) 1992-01-30 1992-01-30 Materiau conducteur de haute durete et procede de fabrication de ce materiau.
FR9201026 1992-01-30
PCT/FR1993/000089 WO1993015240A1 (fr) 1992-01-30 1993-01-28 Materiau conducteur de haute durete et procede de fabrication de ce materiau

Publications (2)

Publication Number Publication Date
EP0624206A1 EP0624206A1 (de) 1994-11-17
EP0624206B1 true EP0624206B1 (de) 1995-10-11

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EP93904133A Expired - Lifetime EP0624206B1 (de) 1992-01-30 1993-01-28 Leitfähiges material mit hoher härte und verfahren zu seiner herstellung

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EP (1) EP0624206B1 (de)
DE (1) DE69300632T2 (de)
FR (1) FR2686903B1 (de)
WO (1) WO1993015240A1 (de)

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR902206A (fr) * 1943-02-27 1945-08-22 Philips Nv Procédé de durcissement superficiel d'alliages métalliques et objets réalisés avec ces alliages durcis
DE1173764B (de) * 1957-05-23 1964-07-09 Siemens Ag Verfahren zur Herstellung abriebfester Oberflaechenschichten grosser Haerte und Leitfaehigkeit, insbesondere fuer elektrische Gleit- und Reibkontakte
NL260208A (de) * 1960-02-16
DE1807906B2 (de) * 1968-01-27 1971-09-09 Verfahren zur herstellung von hochfesten elektrisch hochlei tenden und waermebestaendigen materialien
US3922180A (en) * 1970-04-01 1975-11-25 Bell Telephone Labor Inc Method for oxidation-hardening metal alloy compositions, and compositions and structures therefrom
USRE31902E (en) * 1980-05-02 1985-05-28 Scm Corporation Dispersion strengthened metals

Also Published As

Publication number Publication date
WO1993015240A1 (fr) 1993-08-05
DE69300632T2 (de) 1996-05-09
FR2686903A1 (fr) 1993-08-06
FR2686903B1 (fr) 1994-03-18
EP0624206A1 (de) 1994-11-17
DE69300632D1 (de) 1995-11-16

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