US3109053A - Insulated conductor - Google Patents

Insulated conductor Download PDF

Info

Publication number
US3109053A
US3109053A US80738A US8073861A US3109053A US 3109053 A US3109053 A US 3109053A US 80738 A US80738 A US 80738A US 8073861 A US8073861 A US 8073861A US 3109053 A US3109053 A US 3109053A
Authority
US
United States
Prior art keywords
copper
ceramic
insulated conductor
layer
conductor
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
US80738A
Inventor
Ahearn John Francis
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.)
Raytheon Co
Original Assignee
Raytheon Co
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Raytheon Co filed Critical Raytheon Co
Priority to US80738A priority Critical patent/US3109053A/en
Priority to BE608288A priority patent/BE608288A/en
Application granted granted Critical
Publication of US3109053A publication Critical patent/US3109053A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
    • H01B3/02—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances
    • H01B3/10—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances metallic oxides
    • H01B3/105—Wires with oxides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
    • H01B3/02—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances
    • H01B3/08—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of inorganic substances quartz; glass; glass wool; slag wool; vitreous enamels
    • H01B3/082—Wires with glass or glass wool

Definitions

  • Insulated conductors for high temperature service have employed as insulation either a Fiberglas serving or a ceramic coating. Fiber-glas is capable of withstanding temperatures up to about 650 C. Without deterioration of the insulation.
  • the space factor of Fiberglas served magnet Wires is very poor compared with most organic film insulated wires. The relative volume occupied by the insulation becomes increasingly greater as the diameter of the wire becomes smaller, with the result that the volume of copper Wire, for instance, in a typical magnet coil winding is only about 11 percent of the total volume of the winding.
  • the volume of conductor is 23 percent of the total volume.
  • Ceramic coatings have been applied in very thin layers to metal, yielding an insulated wire of space factor equivalent to or better than that of organic film coated conductors.
  • no method was known whereby an adherent, flexible ceramic coating could be applied to popular conductor metals, such as silver and copper.
  • Methods are known for applying inorganic oxide coatings to aluminum by means of the anodizing process.
  • aluminum has only 61 percent of the conductivity of annealed copper and is therefore not suitable for applications in which size and weight are important considerations.
  • the low melting point of aluminum 650 C.) limits its use to temperatures less than about 500 C.
  • Ceramic insulation comprising refractory oxides bonded with glass has been applied with considerable success to nickel clad copper wires.
  • Such coatings exhibit a remarkable degree of adherence and flexibility due to the fact that a molecular bond exists between the nickel base metal, a diffused nickel oxide, and the ceramic-glass insulating layer.
  • nickel clad wires which have been successfully coated with ceramic have initially only about 70 percent of the conductivity of pure copper, and upon aging at elevated temperatures, a portion of the nickel diffuses into the copper core of such wires forming a copper-nickel alloy of much higher resistance than pure copper. Consequently, aging of nickel clad copper wires at elevated temperatures even in the absence of air results in a permanent increase in the resistance of the Wire. The extent of resistance increase is dependent on the wire diameter, the temperature, and the time of exposure to high temperature.
  • a high temperature insulated conductor is prepared by plating or otherwise imposing upon a high conductivity base metal A (such as silver or copper) a layer B of chromium, rhenium or iron or alloys thereof so as to comprise roughly from 1 to 10 percent of the total volume of the conductor.
  • the precise proportion by weight of the plating metal or alloy to the base metal varies with the diameter of the wire but should be suflicient to protect the base metal conductor from the effects of oxidation when heated in air to 800 C. for a period of five minutes.
  • Methods of electro-plating or forming chromium, rhenium or iron on copper or silver are known to the art and do not constitute a part of this invention.
  • an oxidized surface is caused to form upon the plating metal or alloy by any of several possible methods, among which are (1) heating in air or oxygen for short periods at 600 to 800 C., (2) anodizing in an electrolytic bath, or (3) coating with a ceramic composition containing an oxidizing agent and heating briefly to the curing temperature of the ceramic.
  • the inventor has discovered that by such means, an oxidized surface may be formed on the plating which provides a suitable base for the subsequent application of ceramic C or vitreous insulating coatings.
  • the adherence of such coatings to the oxidized surface of plating metal or alloy is excellent, whereas it has been found that vitreous coatings show little or no adherence to such metals or alloys which are not oxidized.
  • sufiicient oxidation of the plating metal or alloy occurs even Without the presence of an oxidizing agent in the ceramic formulation.
  • High temperatures and long curing times promote natural oxidation of the plating surface. It is desirable to roughen the plating surface by sandblasting, acid etching, or other means in order to further promote adherence to the vitreous coating.
  • the exact formulation of the ceramic coating may vary over a wide range of composition.
  • glassy bonding agents are: lead borate, lead silicate, and combinations of the two, and mixtures of sodium, calcium, and potassium silicates.
  • Refractory components mixed with the bonding agent may be, for example, aluminum oxide, titanium oxide, Zirconium oxide, beryllium oxide, finely ground natural and synthetic micas, or finely chopped fibers of quartz, aluminum silicate, potassium titanate, or asbestos. These and other refractory materials may be admixed with glassy bonding agents to obtain ceramic coatings having a variety of properties.
  • the coating may be applied by known methods such as drag coating or electrophoresis.
  • a fluoride coating may be formed on such metals or alloys thereof by heating in fluorine, hydrogen fluoride, or fluorocarbon gas.
  • the wire coated with chromium, rhenium or iron, or alloys thereof may be made the anode in a non-aqueous electrolytic bath containing hydrogen fluoride. The fluoride layer so formed is further diffused into the metal coating by heating at elevated temperature, yielding a flexible, adherent, insulating coatmg.
  • the method of the invention is applicable not only to wire but also to other types of conductors such as 3 copper or silver tubing and foil, which are plated with chromium, rhenium, iron or alloys thereof and insulated as described.
  • conductors prepared in accordance with the invention are either completely free from, or exhibit a relatively small degree of the diffusion effects which cause a permanent increase in the resistance of clad Wires hitherto offered for high temperature service.
  • Copper plated with either chromium or rhenium, and silver plated With chromium show negligible change in resistance upon heating for 2,000 hours in argon at 600 C.
  • Copper and silver, iron plated show only a small increase in resistance when heated under similar conditions.
  • the resistance of commercial nickel clad copper wire was found to increase 350 percent in the same test.
  • Other types of commercial clad and plated wires, such as copper clad with Inconel or stainless steel also show large increases in resistance upon prolonged heating in an inert atmosphere.
  • An insulated conductor comprising a body of conductive material selected from the group consisting of copper and silver, a first layer covering said body, said first layer being a metal selected from the group consisting of chromium, rheniurn and iron and alloys thereof, and a second layer covering said first layer, said second layer comprising particles of refractory material.
  • An insulated conductor comprising a core of copper, a layer of rhenium on said core, and a second layer covering said rhenium layer and comprising particles of refractory material.
  • An insulated conductor comprising a core of silver, a layer of chromium on said core, and a second layer covering said chromium layer and comprising particles of refractory material.

Description

Oct. 29, 1963 J. F. AHEARN INSULATED CONDUCTOR Filed Jan. 5, 1961 BONDIN VITREOUS MATERIALS LEAD BORATE LEAD SILICATE (combinations of above) MIXTURE OF SODIUM POTASSIUM SILICATES CALCIUM SILICATES REFRACTORY MIXED WITH BONDING AGENT ALUMINUM OXIDE TITANIUM OXIDE ZIRCONIUM OXIDE BERYLLIUM OXIDE GROUND MICA QUARTZ FIBRE ALUMINUM SILICATE POTASSIUM TITANATE ASBESTOS OTHERS FLUORIDE COMPOUND INVENTOR JOHN FRA/VC/S AHEA/P/V er I? M SILVER COPPER AGE/VT United States Patent 3,109,053 INSULATED CONDUCTOR John Francis Ahearn, Reading, Mass., assignor to Raytheon Company, Lexington, Mass., a corporation of Delaware Filed Jan. 5, 1961, Ser. No. 80,738 4 Claims. (Cl. 174110) This invention relates to methods and means of con struction of insulated conductors such as magnet wires and ribbon conductors which are required to operate at elevated temperatures.
Insulated conductors for high temperature service have employed as insulation either a Fiberglas serving or a ceramic coating. Fiber-glas is capable of withstanding temperatures up to about 650 C. Without deterioration of the insulation. However, due to the bulk of the Fiberglas serving, the space factor of Fiberglas served magnet Wires is very poor compared with most organic film insulated wires. The relative volume occupied by the insulation becomes increasingly greater as the diameter of the wire becomes smaller, with the result that the volume of copper Wire, for instance, in a typical magnet coil winding is only about 11 percent of the total volume of the winding. Using single glass serving, the volume of conductor is 23 percent of the total volume. These values are very :low compared with the space factor of 55 percent for many conventional organic film coated wires. Therefore, any major improvements in space factor of glass served wires is most difiicult because of the minimum size of yarn which can be produced and handled on Wireserving machinery.
Ceramic coatings have been applied in very thin layers to metal, yielding an insulated wire of space factor equivalent to or better than that of organic film coated conductors. However, prior to the present invention, no method was known whereby an adherent, flexible ceramic coating could be applied to popular conductor metals, such as silver and copper. Methods are known for applying inorganic oxide coatings to aluminum by means of the anodizing process. However, aluminum has only 61 percent of the conductivity of annealed copper and is therefore not suitable for applications in which size and weight are important considerations. In addition, the low melting point of aluminum (650 C.) limits its use to temperatures less than about 500 C. Ceramic insulation comprising refractory oxides bonded with glass has been applied with considerable success to nickel clad copper wires. Such coatings exhibit a remarkable degree of adherence and flexibility due to the fact that a molecular bond exists between the nickel base metal, a diffused nickel oxide, and the ceramic-glass insulating layer. However, nickel clad wires :which have been successfully coated with ceramic have initially only about 70 percent of the conductivity of pure copper, and upon aging at elevated temperatures, a portion of the nickel diffuses into the copper core of such wires forming a copper-nickel alloy of much higher resistance than pure copper. Consequently, aging of nickel clad copper wires at elevated temperatures even in the absence of air results in a permanent increase in the resistance of the Wire. The extent of resistance increase is dependent on the wire diameter, the temperature, and the time of exposure to high temperature.
The lack of an available high temperature insulated conductor combining the desirable properties of good space factor, high conductivity, thermal stability, flexibility and mechanical durability has imposed a severe handicap on the design of electronic equipment which is required to operate at temperatures of 250 to 600 C. It is an object of the present invention to provide an insulated "ice conductor having the above-mentioned requirements and which exhibits little or no change in resistance when subjected to prolonged exposure to elevated temperatures up to 600 C. The single FIGURE shows a laminated structure embodying my invention, the composition of the various laminae also being listed.
In accordance with the present invention and as illustrated on the drawing, a high temperature insulated conductor is prepared by plating or otherwise imposing upon a high conductivity base metal A (such as silver or copper) a layer B of chromium, rhenium or iron or alloys thereof so as to comprise roughly from 1 to 10 percent of the total volume of the conductor. The precise proportion by weight of the plating metal or alloy to the base metal varies with the diameter of the wire but should be suflicient to protect the base metal conductor from the effects of oxidation when heated in air to 800 C. for a period of five minutes. Methods of electro-plating or forming chromium, rhenium or iron on copper or silver are known to the art and do not constitute a part of this invention.
Subsequent to platin an oxidized surface is caused to form upon the plating metal or alloy by any of several possible methods, among which are (1) heating in air or oxygen for short periods at 600 to 800 C., (2) anodizing in an electrolytic bath, or (3) coating with a ceramic composition containing an oxidizing agent and heating briefly to the curing temperature of the ceramic. The inventor has discovered that by such means, an oxidized surface may be formed on the plating which provides a suitable base for the subsequent application of ceramic C or vitreous insulating coatings. The adherence of such coatings to the oxidized surface of plating metal or alloy is excellent, whereas it has been found that vitreous coatings show little or no adherence to such metals or alloys which are not oxidized. Under certain conditions with some ceramic formulations, sufiicient oxidation of the plating metal or alloy occurs even Without the presence of an oxidizing agent in the ceramic formulation. High temperatures and long curing times promote natural oxidation of the plating surface. It is desirable to roughen the plating surface by sandblasting, acid etching, or other means in order to further promote adherence to the vitreous coating.
The exact formulation of the ceramic coating may vary over a wide range of composition. Examples of glassy bonding agents are: lead borate, lead silicate, and combinations of the two, and mixtures of sodium, calcium, and potassium silicates. Refractory components mixed with the bonding agent may be, for example, aluminum oxide, titanium oxide, Zirconium oxide, beryllium oxide, finely ground natural and synthetic micas, or finely chopped fibers of quartz, aluminum silicate, potassium titanate, or asbestos. These and other refractory materials may be admixed with glassy bonding agents to obtain ceramic coatings having a variety of properties. The coating may be applied by known methods such as drag coating or electrophoresis.
Other methods of bonding inorganic insulating coatings to a chromium, rhenium, or iron base may be employed within the scope of the invention. For example, a fluoride coating may be formed on such metals or alloys thereof by heating in fluorine, hydrogen fluoride, or fluorocarbon gas. Alternatively, the wire coated with chromium, rhenium or iron, or alloys thereof, may be made the anode in a non-aqueous electrolytic bath containing hydrogen fluoride. The fluoride layer so formed is further diffused into the metal coating by heating at elevated temperature, yielding a flexible, adherent, insulating coatmg.
The method of the invention is applicable not only to wire but also to other types of conductors such as 3 copper or silver tubing and foil, which are plated with chromium, rhenium, iron or alloys thereof and insulated as described.
It has been found that conductors prepared in accordance with the invention are either completely free from, or exhibit a relatively small degree of the diffusion effects which cause a permanent increase in the resistance of clad Wires hitherto offered for high temperature service. Copper plated with either chromium or rhenium, and silver plated With chromium, show negligible change in resistance upon heating for 2,000 hours in argon at 600 C. Copper and silver, iron plated, show only a small increase in resistance when heated under similar conditions. By way of contrast, the resistance of commercial nickel clad copper wire was found to increase 350 percent in the same test. Other types of commercial clad and plated wires, such as copper clad with Inconel or stainless steel also show large increases in resistance upon prolonged heating in an inert atmosphere.
While there is described herein methods and means of construction of a ceramic coated or inorganic material coated conductor forming a Wire for use in, for example, a magnet coil it should be clearly understood that these examples in no way limit the scope of the invention. It is apparent that the methods and structures disclosed herein are applicable to other uses particularly where it is desirable to insulate a conductor with a thin coating of temperature resistant insulation. The scope of the invention is set forth in the accompanying claims.
What is claimed is:
1. An insulated conductor comprising a body of conductive material selected from the group consisting of copper and silver, a first layer covering said body, said first layer being a metal selected from the group consisting of chromium, rheniurn and iron and alloys thereof, and a second layer covering said first layer, said second layer comprising particles of refractory material.
2. An insulated conductor as set forth in claim 1 wherein the second layer is a vitreous material.
3. An insulated conductor comprising a core of copper, a layer of rhenium on said core, and a second layer covering said rhenium layer and comprising particles of refractory material.
4. An insulated conductor comprising a core of silver, a layer of chromium on said core, and a second layer covering said chromium layer and comprising particles of refractory material.
References Cited in the file of this patent UNITED STATES PATENTS

Claims (1)

1. AN INSULATED CONDUCTOR COMPRISING A BODY OF CONDUCTIVE MATERIAL SELECTED FROM THE GROUP CONSISTING OF COPPER AND SILVER, A FIRST LAYER COVERING SAID BODY, SAID
US80738A 1961-01-05 1961-01-05 Insulated conductor Expired - Lifetime US3109053A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US80738A US3109053A (en) 1961-01-05 1961-01-05 Insulated conductor
BE608288A BE608288A (en) 1961-01-05 1961-09-18 Improvement in insulated conductors.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US80738A US3109053A (en) 1961-01-05 1961-01-05 Insulated conductor

Publications (1)

Publication Number Publication Date
US3109053A true US3109053A (en) 1963-10-29

Family

ID=22159291

Family Applications (1)

Application Number Title Priority Date Filing Date
US80738A Expired - Lifetime US3109053A (en) 1961-01-05 1961-01-05 Insulated conductor

Country Status (2)

Country Link
US (1) US3109053A (en)
BE (1) BE608288A (en)

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3222219A (en) * 1961-11-29 1965-12-07 Phelps Dodge Copper Prod Ceramic-coated electrically-conductive wire and method of making same
US3356982A (en) * 1964-04-13 1967-12-05 Angstrohm Prec Inc Metal film resistor for low range and linear temperature coefficient
US3442993A (en) * 1962-12-17 1969-05-06 Nippon Electric Co Vitreous material for use in semiconductor devices
US3514652A (en) * 1969-02-25 1970-05-26 Emerson Electric Co Hermetic motors
US4079192A (en) * 1973-06-12 1978-03-14 Bernard Josse Conductor for reducing leakage at high frequencies
US4246317A (en) * 1979-03-26 1981-01-20 United States Steel Corporation Silicate coated metal tying wire and process for coating said wire
US4294867A (en) * 1980-08-15 1981-10-13 Ford Motor Company Method for developing a pattern on a ceramic substrate
US4424867A (en) 1981-03-31 1984-01-10 Fiberglas Canada Inc. Heat hardening sealant-gel for flexible couplings
US4499334A (en) * 1983-12-22 1985-02-12 The United States Of America As Represented By The Secretary Of The Air Force Heat resistant sheathed insulated electrical conductors
EP0179527A1 (en) * 1984-10-18 1986-04-30 Koninklijke Schelde Groep B.V. Sheathed reinforcing wire
US5105531A (en) * 1989-10-13 1992-04-21 Sumitomo Electric Industries, Ltd. Method of manufacturing a coil of insulated wire
US5246729A (en) * 1986-06-30 1993-09-21 United States Of America As Represented By The Secretary Of The Air Force Method of coating superconductors with inorganic insulation
US5372886A (en) * 1989-03-28 1994-12-13 Sumitomo Electric Industries, Ltd. Insulated wire with an intermediate adhesion layer and an insulating layer
US5443905A (en) * 1991-01-24 1995-08-22 Sumitomo Electric Industries, Ltd. Heat and oxidation resistant composite electrical conductor
US5903539A (en) * 1996-06-18 1999-05-11 Asahi Kogaku Kogyo Kabushiki Kaisha Electromagnetic objective lens driving apparatus of optical data recording and reproducing apparatus
US6190770B1 (en) * 1999-02-12 2001-02-20 Tai-I Electric Wire & Cable Co. Pulsed voltage surge resistant enamelled wires
US20190267532A1 (en) * 2018-02-28 2019-08-29 The Regents Of The University Of Colorado, A Body Corporate Enhanced superconducting transition temperature in electroplated rhenium

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2700212A (en) * 1948-10-15 1955-01-25 Gen Electric Electrical conductor
US2975078A (en) * 1957-10-21 1961-03-14 Cons Electrodynamics Corp Ceramic coated wire

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2700212A (en) * 1948-10-15 1955-01-25 Gen Electric Electrical conductor
US2975078A (en) * 1957-10-21 1961-03-14 Cons Electrodynamics Corp Ceramic coated wire

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3222219A (en) * 1961-11-29 1965-12-07 Phelps Dodge Copper Prod Ceramic-coated electrically-conductive wire and method of making same
US3442993A (en) * 1962-12-17 1969-05-06 Nippon Electric Co Vitreous material for use in semiconductor devices
US3356982A (en) * 1964-04-13 1967-12-05 Angstrohm Prec Inc Metal film resistor for low range and linear temperature coefficient
US3514652A (en) * 1969-02-25 1970-05-26 Emerson Electric Co Hermetic motors
US4079192A (en) * 1973-06-12 1978-03-14 Bernard Josse Conductor for reducing leakage at high frequencies
US4246317A (en) * 1979-03-26 1981-01-20 United States Steel Corporation Silicate coated metal tying wire and process for coating said wire
US4294867A (en) * 1980-08-15 1981-10-13 Ford Motor Company Method for developing a pattern on a ceramic substrate
US4424867A (en) 1981-03-31 1984-01-10 Fiberglas Canada Inc. Heat hardening sealant-gel for flexible couplings
US4499334A (en) * 1983-12-22 1985-02-12 The United States Of America As Represented By The Secretary Of The Air Force Heat resistant sheathed insulated electrical conductors
EP0179527A1 (en) * 1984-10-18 1986-04-30 Koninklijke Schelde Groep B.V. Sheathed reinforcing wire
US5246729A (en) * 1986-06-30 1993-09-21 United States Of America As Represented By The Secretary Of The Air Force Method of coating superconductors with inorganic insulation
US5372886A (en) * 1989-03-28 1994-12-13 Sumitomo Electric Industries, Ltd. Insulated wire with an intermediate adhesion layer and an insulating layer
US5105531A (en) * 1989-10-13 1992-04-21 Sumitomo Electric Industries, Ltd. Method of manufacturing a coil of insulated wire
US5443905A (en) * 1991-01-24 1995-08-22 Sumitomo Electric Industries, Ltd. Heat and oxidation resistant composite electrical conductor
US5477610A (en) * 1991-01-24 1995-12-26 Sumitomo Electric Industries, Ltd. Method of manufacturing composite conductor having heat resistance or oxidation resistance
US5903539A (en) * 1996-06-18 1999-05-11 Asahi Kogaku Kogyo Kabushiki Kaisha Electromagnetic objective lens driving apparatus of optical data recording and reproducing apparatus
US6190770B1 (en) * 1999-02-12 2001-02-20 Tai-I Electric Wire & Cable Co. Pulsed voltage surge resistant enamelled wires
US20190267532A1 (en) * 2018-02-28 2019-08-29 The Regents Of The University Of Colorado, A Body Corporate Enhanced superconducting transition temperature in electroplated rhenium
US10741742B2 (en) * 2018-02-28 2020-08-11 The Regents Of The University Of Colorado, A Body Corporate Enhanced superconducting transition temperature in electroplated rhenium
US11018290B2 (en) 2018-02-28 2021-05-25 The Regents Of The University Of Colorado, A Body Corporate Enhanced superconducting transition temperature in electroplated rhenium
US11309478B2 (en) 2018-02-28 2022-04-19 The Regents Of The University Of Colorado, A Body Corporate Enhanced superconducting transition temperature in electroplated Rhenium

Also Published As

Publication number Publication date
BE608288A (en) 1962-01-15

Similar Documents

Publication Publication Date Title
US3109053A (en) Insulated conductor
US2975078A (en) Ceramic coated wire
US4429007A (en) Electrical wire insulation and electromagnetic coil
US5436409A (en) Electrical conductor member such as a wire with an inorganic insulating coating
US2745898A (en) Insulated electric conductors
US2885826A (en) Glass-to-metal seals
US2588920A (en) Method of applying a vitreous coating composition to a glass base and article resulting thereform
US2863782A (en) Low-melting high-expansion glass
KR102417281B1 (en) airtight terminal
EP0188370A2 (en) Electrical wire with refractory coating
US5246729A (en) Method of coating superconductors with inorganic insulation
US3310433A (en) Ceramic article coated with silver containing oxygen and method of making same
US5212013A (en) Inorganic wire insulation for super-conducting wire
JPH0125166B2 (en)
JPS6161526B2 (en)
JPH05205534A (en) Heat resistive insulated wire
JPS621242B2 (en)
US3513080A (en) Coated sintered conductor
US2465105A (en) Oxide insulating coating for nickel chromium resistance wire
JPS63318011A (en) Heat resistant insulated electric wire
US3475144A (en) Composite metal conductor sealed to glass
JP3228520B2 (en) Vacuum wire
EP0729157B1 (en) Electrical conductor member such as a wire with an inorganic insulating coating
US3115432A (en) Method for producing high temperature electrical insulation
JPH02270217A (en) Insulated wire