Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F6/00—Superconducting magnets; Superconducting coils
  • H01F6/06—Coils, e.g. winding, insulating, terminating or casing arrangements therefor
• • 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
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
  • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
  • H01F41/04—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing coils
  • H01F41/12—Insulating of windings
  • H01F41/122—Insulating between turns or between winding layers
• • 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
  • Y10S505/00—Superconductor technology: apparatus, material, process
  • Y10S505/825—Apparatus per se, device per se, or process of making or operating same
  • Y10S505/917—Mechanically manufacturing superconductor
  • Y10S505/918—Mechanically manufacturing superconductor with metallurgical heat treating
  • Y10S505/919—Reactive formation of superconducting intermetallic compound
• • 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
  • Y10S505/00—Superconductor technology: apparatus, material, process
  • Y10S505/825—Apparatus per se, device per se, or process of making or operating same
  • Y10S505/917—Mechanically manufacturing superconductor
  • Y10S505/918—Mechanically manufacturing superconductor with metallurgical heat treating
  • Y10S505/919—Reactive formation of superconducting intermetallic compound
  • Y10S505/921—Metal working prior to treating
• • 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
  • Y10S505/00—Superconductor technology: apparatus, material, process
  • Y10S505/825—Apparatus per se, device per se, or process of making or operating same
  • Y10S505/917—Mechanically manufacturing superconductor
  • Y10S505/924—Making superconductive magnet or coil
• • 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
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49002—Electrical device making
  • Y10T29/49014—Superconductor
• • 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
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49002—Electrical device making
  • Y10T29/4902—Electromagnet, transformer or inductor
  • Y10T29/49071—Electromagnet, transformer or inductor by winding or coiling

Definitions

• the invention relates to a method for the isolation of superconductors in a magnetic winding, in which sizes and / or binders containing organic substances deposited on heat-resistant insulation agents are removed prior to in-situ annealing of conductor pre-products provided to form the superconducting properties of the conductors.
• Superconducting intermetallic compounds of type A 3 B with an A15 crystal structure, such as Nb 3 Sn or V 3 Ga, have good superconducting properties and are distinguished by high critical values. Conductors with these materials are therefore particularly suitable for superconducting magnet coils for generating strong magnetic fields. In addition to these binary connections ternary compounds such as niobium-aluminum-germanium Nb 3 Al 0.8 Ge 0.2 are also particularly interesting for conductors of such magnets.
• a first component which is a wire-shaped ductile element of the intermetallic compound to be produced, is generally surrounded by a sheath which consists of a ductile carrier metal and an alloy containing the other elements of the compound consists.
• a niobium or vanadium wire is surrounded by a sheath made of a copper-tin-bronze or a copper-gallium-bronze.
• a large number of such wires can also be embedded in a matrix made of the alloy.
• the structure obtained from these two components is then subjected to a cross-sectional machining. This results in a long wire-shaped structure, as is required for coils, without reactions which would embrittle the conductor.
• the super conductor of a superconductor consisting of one or more wire cores and the surrounding matrix material is then subjected to an annealing treatment in such a way that the desired superconducting compound having an A15 crystal structure is subjected to a. Reaction of the core material with that in the surrounding Matrix included: another element of the connection is formed. The element contained in the matrix diffuses into the core material consisting of the other element of the connection (cf. German Offenlegungsschrift 20 44 660).
• Superconducting magnetic coils made from such superconductors are generally produced by two different processes.
• the first method which is also referred to as the "react first-wind then method”
• the preliminary conductor product of the superconductor to be produced is wound onto a provisional winding body and then subjected to the annealing treatment required to form the desired superconducting compound.
• the superconductor thus produced is then unwound again from the provisional winding body and can be processed further.
• Sizes for fibers made from the insulating materials mentioned can consist of an adhesive and film former, a lubricant and a wetting agent. If necessary, additives for adhesives can also be provided. These sizes contain, for example, starch, dextrin or polyvinyl acetate (PVAC) as adhesives and film formers, usually vegetable fats or oils as lubricants and surface-active substances as wetting agents. Binders for fabrics or nonwovens from the insulating materials mentioned generally contain organic substances based on lacquer or wax. Such binders are, for example, polyurethane or polyvinyl butyral.
• the pre-products are generally braided or wound with glass or quartz threads.
• the insulations created in this way are generally 'still impregnated with a binder based on paint or wax. Even so, simple wrapping does not offer sufficient security against interturn turns.
• Multiple braidings or braids are therefore provided, which, however, entail a substantial increase in thickness and therefore, in particular in the case of thin conductors, a corresponding reduction in the winding density in the winding. Due to the higher induction voltage between the layers of a winding and for winding reasons, layer insulation made of glass fabrics is generally used.
• the magnetic windings are generally subjected to a cleaning annealing at temperatures between, for example, 250 ° C. and 400 ° C. before the diffusion annealing of the conductor preliminary products. Carried out in a vacuum or in air, losses of the more volatile fractions of the intermediate conductor product, for example of tin, can occur, which deteriorate the current carrying capacity of the subsequently annealed superconductor.
• oxides can form on the matrix material, which diffuse into the glass material at higher temperatures, for example above 700 ° C., and form a complete one Embrittlement and a decrease in the melting point of the glass.
• the cleaning annealing is carried out under protective gas such as argon, the organic substances are only partially driven out of the winding; the rest decomposes to graphite in the subsequent diffusion annealing. This worsens the insulation and can lead to short circuits in the winding.
• This object is achieved for the above-mentioned method in that first the sizes and / or binders are completely removed from the insulation means and instead at least a part of the insulation means is provided with a protective material of predetermined composition, then the magnetic winding with the conductor preliminary products and Insulation means is built up and that the protective material is then removed from the magnetic winding without residue before the in-situ annealing.
• parts for winding insulation and parts for layer insulation are provided as insulation means and after removal of the sizes and / or binders only the parts for layer insulation are provided with the protective material.
• glass, ceramic or quartz threads can be provided as parts for the winding insulation, which are arranged parallel to the conductor preliminary products.
• the loss of strength of the glass, ceramic or quartz threads associated with the desizing process is in fact of only minor importance, since the quartz, ceramic or glass threads placed in parallel are hardly subjected to any mechanical stress. In this way, the parts for winding insulation can be excluded from the outset as the cause of any deterioration in the insulation.
• a protective material with a dye additive can advantageously be used.
• the complete removal of the protective material from the wound, not yet annealed magnet coil can be determined optically by means of a solvent.
• This wire-shaped pre-product is then applied to the winding body of the magnet winding together with the pre-product using a glass thread, the thickness of which corresponds to the thickness of the pre-product.
• the glass filament has been thermally desized beforehand by annealing for about 30 minutes at about 500 ° C. in air.
• the associated loss of strength of the glass thread is of secondary importance, since the glass thread placed parallel to the preliminary conductor product is hardly subjected to any mechanical stress.
• any cracks in the glass thread that occur can be easily repaired by simply placing such threads together without loss of insulation.
• an adaptation can be carried out by connecting several conductors of the same or different type in parallel.
• the conductor preliminary products can therefore run into the winding next to each other without being insulated, multiple turns being insulated from one another by a glass thread.
• the aspect ratios of the conductors can thus be increased without the conductors' current carrying capacity being impaired due to anisotropy effects. A favorable winding density is achieved.
• the tissue stability is therefore significantly increased by impregnating the tissue with a small amount of a suitable lacquer or wax.
• Suitable lacquers are, for example, those that coat the quartz with a protective film and then again with a solvent or through have a thermal treatment completely removed.
• a solution which contains 5 to 20 g of a polyvinyl butyral (for example from Farbwerke Hoechst AG, Frankfurt-Hoechst: Mowital B 60 H) in liters of acetone can advantageously be provided as the impregnating agent.
• the impregnation and a later extraction can be easily controlled by adding a dye (eg from E. Merck, Darmstadt: Victoria blue 4R).
• the desized fabric is thus pulled through a solution and then dried, for example in air. After a few minutes, the quartz fabrics treated in this way are dimensionally stable and are no longer pushed through even by conductors with a diameter of 0.4 mm.
• the bobbin assembly finished with the preliminary conductor product and the parallel, stripped threads and with the prepared quartz fabrics, is then wrapped with a few layers of plastic film (Farbtechnike Hoechst AG, Frankfurt-Hoechst: Hostaphan) and provisionally bandaged with a self-welding winding tape, for example, in a liquid-tight manner.
• the impregnant can then be extracted using a solvent.
• Suitable solvents of the impregnating agent mentioned are, for example, ketones such as acetone, alcohols such as methanol or ether such as methyl glycol.
• the washout is very facilitated in the case of a special construction of a coil former, which is known from DE-OS 27 09 300.
• This coil body has an integrated inlet and outlet system for form-free pressure impregnation.
• the solvent only has to pass through a lower hose nozzle when the coil body is at an angle or vertically in and out through an upper hose nozzle.
• the washing-out process of the impregnating agent can expediently be carried out continuously with a special extraction apparatus. The extraction is complete when the solvent no longer contains any added dye, ie it comes out colorless from the coil.
• the washout process can take 10 to 15 hours, for example.
• the coil is then dried, for example under vacuum or in a gas stream.
• the reaction annealing can then be carried out, in which the niobium of the wire cores is reacted with the tin from the bronze by diffusion to form the intermetallic compound Nb 3 Sn.
• a graphite formation in the winding and thus a deterioration in insulation is excluded because all organic constituents of the impregnating agent of the quartz fabric have been washed out by the previous washing process and glass threads that have already been completely desized from the conductor preliminary product have been applied to the winding body.
• the coil can still be impregnated.
• Low molecular weight polyethylenes with mol weights between 1000 and 8000 can advantageously be used as the impregnating agent. These polyethylenes have sufficiently high solidification temperatures between 100 ° C and 120 ° C, even at room temperature nonmechanical relatively strong and comparable s c hlechtern the training behavior of the coils. At processing temperatures between 120 ° C and 160 ° C , their viscosities are between about 0.03 and 3 Pas low enough for vacuum impregnation of tightly wound magnets.
• the protective material for the insulating fabrics is completely removed from the magnetic winding by washing with a suitable solvent.
• a thermal treatment for driving these materials out of the winding can optionally also be provided.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
• Superconductors And Manufacturing Methods Therefor (AREA)

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• 1978
  • 1978-08-25 DE DE2837199A patent/DE2837199C2/de not_active Expired
• 1979
  • 1979-08-10 US US06/065,628 patent/US4261097A/en not_active Expired - Lifetime
  • 1979-08-13 EP EP79102948A patent/EP0008431B1/fr not_active Expired

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