[go: up one dir, main page]

EP3650568A1 - Alliage de niobium-étain et son procédé de fabrication - Google Patents

Alliage de niobium-étain et son procédé de fabrication Download PDF

Info

Publication number
EP3650568A1
EP3650568A1 EP18204539.3A EP18204539A EP3650568A1 EP 3650568 A1 EP3650568 A1 EP 3650568A1 EP 18204539 A EP18204539 A EP 18204539A EP 3650568 A1 EP3650568 A1 EP 3650568A1
Authority
EP
European Patent Office
Prior art keywords
niobium
alloy
weight
tin
rod
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.)
Withdrawn
Application number
EP18204539.3A
Other languages
German (de)
English (en)
Inventor
Bernd Spaniol
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Priority to EP18204539.3A priority Critical patent/EP3650568A1/fr
Publication of EP3650568A1 publication Critical patent/EP3650568A1/fr
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C27/00—Alloys based on rhenium or a refractory metal not mentioned in groups C22C14/00 or C22C16/00
    • C22C27/02—Alloys based on vanadium, niobium, or tantalum
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/16—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of other metals or alloys based thereon
    • C22F1/18—High-melting or refractory metals or alloys based thereon

Definitions

  • the invention relates to a niobium alloy for the production of Nb 3 Sn superconductors.
  • the invention also relates to a rod made of such a niobium alloy and a preliminary product comprising such a niobium alloy for the production of superconducting cables.
  • the invention further relates to a production method for such a niobium alloy, a niobium alloy obtainable by the method and the use of such a niobium alloy for the production of superconducting cables containing Nb 3 Sn.
  • Nb 3 Sn is an intermetallic compound from the group of niobium-tin compounds (Nb-Sn compounds).
  • the phases Nb 6 Sn 5 and NbSn 2 are known (see also Figure 1 ).
  • Nb 3 Sn crystallizes in the so-called A15 phase and is a Type II superconductor with a transition temperature of 18.3 K.
  • Nb 3 Sn is an extremely brittle material that cannot be processed directly into wires for superconducting coils. For the practical use of the connection in superconducting wires and cables, ductile precursors are therefore usually assumed.
  • the so-called bronze process is used to produce superconducting wires, in which a cylindrical shaped body made of bronze is assumed.
  • a bronze process is, for example, from the US 4,055,887 A. and the JP 2001 176 345 A known.
  • the bronze is pierced with holes into which rods made of niobium or NbTa are inserted.
  • the outer surface of the bronze rod is thinly coated with tantalum and coated with a copper matrix to improve the drawing properties.
  • the wire drawn from this bronze rod can now be wound into any shape, but is not superconducting. It obtains this property only by heating to a temperature of approx. 700 ° C. Tin diffuses from the bronze into the niobium wires.
  • the annealing is stopped when the composition Nb 3 Sn is generated in sufficient quantity in the wires.
  • the tantalum barrier prevents tin from diffusing out into the copper cladding during the annealing process.
  • the wires are superconducting but also mechanically very sensitive, which means that the superconducting Nb 3 Sn can break even with a slight bend in the wires.
  • niobium rods are used as the starting material.
  • Decisive for the processing to the finished conductor is a grain size that is as small as possible and a small shape memory effect in order to ensure a uniform, regular geometry during processing. These facilitate the reshaping and increase the critical current intensity to be achieved in the superconductor.
  • Nb 3 Sn can be obtained by reacting the elements at 900 to 1000 ° C or by reacting NbSn 2 with niobium and a small amount of copper as a catalyst at 600 ° C.
  • niobium (V) chloride and tin (II) chloride can be converted to Nb 3 Sn at temperatures below 1000 ° C., gaseous hydrogen chloride being obtained as a by-product.
  • a general object of the present invention is to at least partially overcome the disadvantages of the prior art.
  • Another object of the present invention is to find a way with which the production of wires from Nb 3 Sn and moldings containing Nb 3 Sn is possible as simply as possible. It is also an object of the invention to provide a method which enables the preparation of the intermetallic compound Nb 3 Sn and a suitable preliminary product thereof. The process should be as simple and inexpensive to implement as possible. In addition, the grain sizes in the material should be kept as small as possible.
  • niobium alloy for the production of Nb 3 Sn superconductors comprising 0.01 to 8.0% by weight of tin, the remainder being niobium, including impurities due to melting.
  • Melting-related impurities are to be understood as impurities as defined in ASTM standard B391. Such impurities are unavoidable in the representation of niobium in metallic form and cannot be reduced without considerable expense.
  • the Nb alloy has 0.2 to 8.0% by weight of tin, the Nb alloy preferably having 0.2 to 4.0% by weight of tin.
  • the Nb alloy has at least 50% by weight of niobium, the Nb alloy preferably having at least 71% by weight of niobium, particularly preferably having at least 91% by weight of niobium.
  • the niobium alloy consists of 2% by weight of tin and 98% by weight of niobium including impurities due to melting.
  • the niobium alloy consists of 4% by weight of tin and 96% by weight of niobium including impurities due to melting.
  • the niobium alloy has up to 20% by weight of a refractory metal, the alloy preferably having between 5% by weight and 10% by weight of the refractory metal.
  • a "refractory metal” is to be understood as the refractory, base metals of subgroup 4 (titanium, zirconium and hafnium), subgroup 5 (vanadium, niobium and tantalum) and subgroup 6 (chromium, molybdenum and tungsten). Their melting point is above that of platinum (1772 ° C). A proportion of 5% by weight of a refractory metal improves the mechanical properties of the superconducting structure, or of a cable produced therefrom.
  • the refractory metal is selected from at least one element from the group consisting of titanium, zirconium, hafnium, vanadium, tantalum, chromium, molybdenum and tungsten, preferably selected from at least one element from the group titanium, vanadium and tantalum.
  • the Nb alloy has at least 0.001% by weight and up to 0.5% by weight of tantalum.
  • Tantalum improves the mechanical properties and in particular the formability of the wires made from the Nb alloy.
  • grains of a microstructure of a rod of the Nb alloy have grain sizes from 5 ⁇ m to 300 ⁇ m, preferably from 10 to 100 ⁇ m, particularly preferably from 10 to 70 ⁇ m and very particularly preferably from 15 to 45 ⁇ m.
  • the diffusion times must be limited to prevent coarse-grained material from being formed.
  • the amount of Nb 3 Sn obtained is negatively overcompensated by earlier quenching. Quenching is understood to mean the transition from superconducting to normal conducting through an external or self-generated magnetic field.
  • the superconducting properties are deteriorated due to an earlier breakdown of the superconductivity with increasing magnetic field, because the material is coarser. Therefore, the smaller grain sizes that can be achieved with the Nb alloy are preferred.
  • the grain sizes can be achieved in the recrystallized state, i.e. they result from forming and annealing. In the present case, the grain size is measured in accordance with ASTM E 112.
  • grain sizes are understood to mean the microstructures present in the form of largely single-crystalline regions within metallic materials.
  • microstructure characterizes the nature of the totality of those sub-volumes, each of which is homogeneous to a first approximation in terms of its composition and the spatial arrangement of its building blocks with respect to a stationary axis cross placed in the material.
  • the structure is characterized by the type, shape, size, distribution and orientation of the structural components.
  • the "degree of deformation” is a shape change parameter with which the permanent geometric change of a workpiece can be recorded during the forming process.
  • a ductile rod made of the niobium alloy has a recrystallization temperature (Trekr) of 1050 ° C to 1300 ° C, preferably from 1100 ° C to 1300 ° C, and particularly preferably from 1150 ° C to 1250 ° C.
  • Rekr recrystallization temperature
  • the later diffusion annealing on the finished conductor can take place at higher temperatures and with longer annealing times than in the prior art, without increasing coarse grain formation in the Nb 3 Zn. This allows a higher proportion of the tin to react to Nb 3 Zn.
  • the lattice constant is given in angstroms.
  • the lattice constant of the alloy is preferably at least 0.01% greater than the lattice constant of the pure niobium. This is approximately achieved with an Sn content of 0.2% by weight of Sn in the Nb alloy.
  • the lattice constants mentioned define the desired alpha phase of the Nb alloy. This can be ensured by the mathematical formula mentioned that the desired alpha phase is realized in the Nb alloy.
  • the lattice constant is understood to mean a length specification which is required to describe a crystal lattice, in particular the unit cell of a crystalline material.
  • the lattice constant is a side length of the unit cell. In the case of cubic lattices, there is only one lattice constant for all three spatial directions, since the unit cell is cubic, i.e. cubic.
  • a ductile rod made of the Nb alloy has a hardness of 90 to 130 HV, preferably a hardness of 90 to 105 HV.
  • the Vickers (HV) hardness values refer to the annealed condition with preferred fine grain structure.
  • a Vickers hardness of 90 HV is only marginally harder than pure niobium, even an Nb alloy with 4 wt.% Sn has 105 to 110 HV.
  • the Nb alloy according to the invention is therefore not too hard in comparison to pure niobium.
  • the Vickers (HV) hardness measurement is carried out in accordance with DIN EN ISO 6507.
  • the objects on which the present invention is based are also achieved by a rod made of such a niobium alloy for the production of superconducting cables.
  • the rod made of the niobium alloy according to the invention can be used directly for the production of superconducting Nb 3 Sn wires using the bronze process.
  • the shaped body made of bronze has a coating made of tantalum.
  • the tantalum serves as a diffusion barrier for the tin, so that the bronze cannot be depleted in Zn and the tin is therefore available for the formation of Nb 3 Sn.
  • a preliminary product for the production of superconducting cables comprising a molded body made of a copper-tin alloy, the molded body having a first and a second side, with a plurality of bores from the first side of the Extend molded body to the second side of the molded body, and the bores contain a niobium alloy according to the invention or rods according to the invention.
  • the preliminary product can be used directly for the production of superconducting wires made of Nb 3 Sn.
  • the preliminary product is therefore particularly suitable and intended for the known bronze processes.
  • a preliminary product for the production of superconducting cables comprising a tube made of a niobium alloy according to the invention, the tube being filled with an intermetallic compound made of niobium and tin.
  • the tube can also be filled with niobium and / or tin.
  • This preliminary product can also be used directly for the production of superconducting wires made of Nb 3 Sn. The preliminary product is therefore particularly suitable and intended for the known powder-in-tube processes.
  • the pressure conversion is carried out in a temperature range from 1000 ° C to 1150 ° C.
  • the pressure forming is carried out by forging, by extrusion and / or by hot rolling.
  • an oxidation layer formed during the pressure-forming process is removed, preferably by a mechanical machining process.
  • the Nb alloy can be better bonded with the bronze in the subsequent bronze process in order to produce the Nb 3 Sn.
  • Oxide particles are brittle and can lead to the filament being torn off and thus to the conductor failure.
  • the melting is carried out at a gas partial pressure of at least 50 mbar, preferably at 150 to 300 mbar.
  • a protective gas preferably an inert gas, particularly preferably helium, is used as the gas.
  • the objects on which the present invention is based are also achieved by a niobium alloy obtainable by such a method according to the invention.
  • niobium alloy according to the invention for the production of superconducting cables comprising Nb 3 Sn by the bronze process or by the powder-in-tube process.
  • the objects on which the present invention is based are also achieved by a superconducting wire using a bronze process from a bronze-coated niobium alloy according to one of claims 1 to 6 or 13 or from a bronze-coated rod according to claim 7, wherein a to the remaining bronze adjacent area consists of Nb 3 Sn phase and inside the Nb 3 Sn phase there is a residue of the niobium alloy in an alpha phase, the alpha phase having an Sn content which is at least as large as the Sn -Content of the niobium alloy used.
  • the alpha phase refers to the binary phase diagram Nb-Sn and is a mixed crystal with less than 12% by weight Sn.
  • the alpha phase is the phase that is adjacent to the pure Nb.
  • the alpha phase can also contain up to 10% of a refractory metal and / or impurities due to melting.
  • the present invention is based on the surprising finding that the addition of small amounts of tin to niobium in the completely miscible alpha phase makes it possible to provide a starting material for the production of superconducting Nb 3 Sn, which on the one hand already contains tin, so that the less diffusion of tin is necessary for the production of the superconducting A15 phase, and the tin in the alpha phase, on the other hand, surprisingly at the same time brings about grain refinement which favors a diffusion of further tin in the niobium and at the same time does not improve the formability in comparison with technical Nb much more difficult.
  • high-quality superconducting wires or wire bundles made of Nb 3 Sn can be produced from the material or from a shaped body, such as a rod or a tube of the material, in a simple and inexpensive manner.
  • the invention consists in particular in an NbSn alloy with 0.01% by weight to 8% by weight of tin (Sn) and the rest niobium (Nb) including common impurities. Alloying with Sn produces a fine grain of the Nb. Because of the extremely different melting points of Sn (232 ° C) and Nb (2468 ° C), direct homogeneous alloying is not possible.
  • Sn leads to a fine-grained alloy which has advantages in terms of grain size, grain size distribution and minimization of the shape memory effect during processing.
  • the addition of Sn can save a portion of the Sn later to be entered into the Nb by diffusion from the bronze, since this portion is already contained in the Nb at the start of the process.
  • Nb 3 Sn A15 phase
  • Sn diffusion This phase represents the actual superconductor.
  • the stoichiometric composition of the intermetallic phase Nb 3 Sn has a Sn content of 29.87% by weight.
  • 30% to 50% of the Nb used is converted into the Nb 3 Sn phase, that is to say about 10 to 17% by weight of Sn are diffused into the Nb.
  • the aim of the present invention is to achieve the highest possible critical current Jc for the superconducting structure to be produced, which has the superconducting Nb 3 Sn phase.
  • the highest possible proportion of Nb 3 Sn leads to a higher critical current Jc. This can be achieved by longer glow times and higher temperatures during the glow. At the same time, however, the grain size of Nb 3 Sn increases due to either higher temperatures or longer glow times for the diffusion of Sn in the Nb matrix. This in turn leads to a degradation of the Jc.
  • the invention overcomes both disadvantages of the technology in several ways: Sn has a strong grain-refining effect with Nb even at a low weight percentage of less than 0.2% by weight. By adding Sn to the Nb alloy, the annealing times and temperatures of the finished conductor can be reduced in order to form the same proportion of A15 phase as without adding Sn alloy. As a result, in addition to the grain-refining effect of Sn, less coarse grain formation and thus a higher critical current strength Jc are achieved.
  • a “vacuum arc melting process” or “remelting in an arc under vacuum”, also “vacuum arc remelting” (VAR) is understood to mean a process known to the person skilled in the art for the controlled mixing and solidification of metals, alloys and intermetallic compounds.
  • VAR vacuum arc remelting
  • a melting electrode with a rectangular or round cross section is remelted into a water-cooled copper crucible of a furnace.
  • the furnace is evacuated and a direct-current arc is ignited between the electrode (cathode) and a so-called starter material on the base of the crucible (anode), also known as “soil protection”.
  • the arc heats both the starter material at the bottom of the crucible and the tip of the electrode, both of which are melted. While the tip of the electrode is being melted, molten material drips into the crucible located below and forms one there pre-reacted molded body. The process maintains a pool of liquid melt that forms a transition area to a fully solidified ingot.
  • the diameter of the crucible is larger than the diameter of the starting electrode or the second shaped body. Therefore, the continuously shrinking electrode can be moved down towards the anode surface in order to maintain a constant mean distance between the electrode tip and the anode pool.
  • vacuum is generally understood to mean working under reduced air pressure. This is preferably understood to mean a pressure of less than 500 mbar, more preferably less than 300 mbar, or 200 mbar, or 50 mbar, or 10 mbar, or less than 1 mbar.
  • tin (chemical symbol Sn) is understood to mean the element tin in metallic form.
  • niobium (chemical symbol Nb) is understood to mean the element niobium in metallic form. The same applies analogously to other chemical elements, such as tantalum.
  • Niobium-tin is understood as a generic term for all known and stable intermetallic niobium-tin compounds, regardless of their stoichiometric composition and the type of crystal lattice.
  • Nb 3 Sn is understood to mean an intermetallic compound composed of 3 niobium atoms and 1 tin atom, this intermetallic compound being essentially crystalline in the A15 phase.
  • intermetallic compound cannot only mean an intermetallic compound with a defined stoichiometric composition per se.
  • the intermetallic compound can also contain free metals, in particular free Nb and / or Sn, as well as alloy constituents and unavoidable impurities.
  • the intermetallic compound can thus also be a composition which, however, has at least one intermetallic compound as such.
  • Nb alloy according to the invention with 0.2% by weight to 8% by weight Sn and a shaped body according to the invention can be carried out, for example, by pre-alloying Nb and Sn by means of arc melting, for example in a vacuum arc melting furnace, with Sn contents of up to 10% by weight, which corresponds approximately to the maximum solubility of Sn in the alpha mixed crystal, or the intermetallic phase Nb 3 Sn (30% by weight Sn) by continuous melting of an Nb sacrificial electrode and continuous Trickling of Sn can be melted.
  • Such methods are also known for the production of the ZrSn50 alloy.
  • the alloy Nb 3 Sn has a melting point of approx. 2130 ° C, which is very close to the melting point of the Nb.
  • an Nb block is alloyed in the electron beam furnace or with VAR, VAR-Skull, VIM Skull or another suitable vacuum melting process to form the Nb alloy according to the invention.
  • This Nb alloy has good processability, since all Sn can be dissolved in the alpha mixed crystal.
  • the Nb alloy is more fine-grained than the pure Nb. This is achieved even with very small amounts of Sn in the Nb alloy.
  • the Nb alloy is formed into a rod by hot working, such as forging or hot rolling. Alloying with Sn reduces the critical degree of deformation of Nb (> 80% with pure Nb).
  • the Sn acts twice as a seed for the recrystallization, as well as for the generation of larger dislocation densities in the Nb.
  • Rods made of this Nb alloy can be drawn into diameters in the ⁇ m range while maintaining their ideal round geometry in the conductor.
  • Nb-Sn phase diagram shows that an alpha phase with higher Sn contents can only be formed and processed at higher temperatures.
  • Nb in the alpha phase has an edge solubility for Sn of 3% by weight at about 800 ° C, 4% by weight at about 960 ° C, 7% by weight at 1400 ° C and 11% by weight .-% at 2180 ° C.
  • Nb alloy of more than 4% by weight is difficult and requires the use of suitable technologies. Processing an Nb alloy of the alpha phase with more than 8% by weight would be extremely complex owing to the high temperatures and the high vapor pressure of the Sn at these temperatures.
  • the phase diagram relates to normal pressure.
  • the alloys NbSn 6.0 wt .-% and NbSn 8.0 wt .-% break even at a forging temperature of 1150 ° C during forging. For these two Nb alloys, therefore, higher temperatures with lower degrees of forming per forming step are necessary so that they can still be processed. In theory, 11% by weight of Sn is soluble in the alpha phase in Nb. However, the processing of such an Nb alloy is too complex, if at all feasible. If Nb alloys with Sn contents> 4.0% are to be used, other forming tests must be carried out.
  • Pure Nb and pure Sn were used for alloying. Alternatively, pure Nb and NbSn alloys can be used.
  • the melting electrodes can be produced by pressing the feed materials Nb (eg chips) and Sn (eg granules).
  • the consumable electrodes can also be produced by pressing Nb and NbSn alloys (pre-alloy) (eg Nb 3 Sn). Solid Nb can also be used as the melting electrode.
  • the Sn or the NbSn master alloy can then be poured into the melt continuously or clocked.
  • All partial-pressure-capable melting processes can be used as melting processes, in which there are no or only minimal reactions between the molten Nb and the crucible materials, such as, for example: VAR, Skull melting process, ARC Skull, VIM Skull, zone melting processes such as VAR are preferred. Due to the zone melting under partial pressure, the Sn evaporation can be neglected.
  • Forging can be done on conventional forging hammers. Forging machines (round forging) can also be used. The forging temperatures have to be adjusted according to the Sn content.
  • NbSn 0.2 % Forge at 1000 ° C NbSn 2.0 % Forge at 1150 ° C
  • the alloys are ductile and can be cold formed in a conventional manner.
  • the excellent ductility decreases with increasing Sn content.
  • the alloys with an Sn content of 0.2% by weight to 4.0% by weight could be easily formed by means of caliber rolls and degrees of deformation of 16% per pass.
  • the recrystallization temperature Trekr increases with increasing Sn content: NbSn 0.2% Trekr 1050 ° C NbSn 2.0% Trekr 1150 ° C NbSn 4.0% Trekr 1250 ° C
  • the lattice constants increase with increasing Sn content. In addition to the blocking effect of Sn, this "distortion" of the lattice also ensures temperature stabilization and the avoidance of coarse grain formation.
  • Table 1 An examination using X-ray diffractometry results in the following tabular lattice constants: material Lattice constant Nb 3.3030 ⁇ NbSn 0.2 3.3035 ⁇ NbSn 2.0 3.3065 ⁇ NbSn 4.0 3.3103 ⁇
  • the lattice constants are determined according to DIN EN 13925-1: 2003-07 with an X-ray diffractometer.
  • the Nb 3 Sn was manufactured by a method as described in the unpublished European patent application no. 17 204 083 is described.
  • Nb electrode rolled profile 32 mm 3600 g
  • VAR melted blocks were forged at 1000 ° C on D 30 mm.
  • the forged blocks were overturned to remove the forging skin and surface oxidation.
  • the forging skin and the superficial oxidation are removed mechanically.
  • the overturned block was cold rolled to a thickness of approximately 10 mm using a rolled profile.
  • the material is ductile and could easily be cold formed.
  • the recrystallization temperature was determined by different annealing temperatures and the grain-refining effect of Sn was demonstrated (see Figure 2 and Table 2).
  • NbSn 0.2% completely recrystallizes at 1150 ° C / 100 min, the hardness after annealing is 91 HV, the grain size is 18 to 50 ⁇ m.
  • the grain size is measured in the examples according to ASTM E 112.
  • the rod is sufficiently ductile for use as a raw material for the production of Nb 3 Sn superconductors after the bronze process.
  • the hardness (HV) is measured here and below in accordance with DIN EN ISO 6507.
  • Figure 2 shows a micrograph of a longitudinal section of the rod thus produced.
  • Nb electrode rolled profile 32 mm 3599 g
  • VAR melted blocks were forged at 1150 ° C on D 30 mm.
  • the forged blocks were overturned to remove the forging skin and surface oxidation.
  • the overturned ingot was cold rolled on a rolled section of approx. 10 mm.
  • the material is ductile and can easily be cold formed.
  • the recrystallization temperature was determined by different annealing temperatures and the grain-refining effect of Sn was demonstrated (see Figures 3 to 5 and Table 2).
  • NbSn 2.0% completely recrystallizes at 1150 ° C / 100 min, the hardness after annealing is 100 to 120 HV, the grain size is 16 to 38 ⁇ m.
  • Annealing at 1250 ° C / 100 min leads to comparable results.
  • the rods are sufficiently ductile to be used as a raw material for the production of Nb 3 Sn superconductors after the bronze process.
  • the Figures 3 to 5 show longitudinal sections of the rods thus produced.
  • the VAR melted block was forged at 1150 ° C at a diameter of 30 mm.
  • the forged block was turned to remove the forging skin and surface oxidation.
  • the overturned ingot was cold rolled on a rolled section of approx. 10 mm.
  • the material is ductile and can easily be cold formed.
  • the recrystallization temperature was determined by different annealing temperatures and the grain-refining effect of Sn was demonstrated (see Figures 6 and 7 and Table 2).
  • NbSn 4.0% completely recrystallizes at 1250 ° C / 100 min, the hardness after annealing is 110 HV, the grain size is 20 to 40 ⁇ m.
  • Annealing at 1250 ° C / 150 min resulted in a hardness of 105 HV and a completely recrystallized grain size of 20 to 45 ⁇ m.
  • the rod is sufficiently ductile to be used as a raw material for the production of Nb 3 Sn superconductors after the bronze process.
  • Figures 6 and 7 show longitudinal sections of the rods thus produced, wherein Figure 6 shows the longitudinal grinding of a rod, which at 1250 ° C for 100 min. was annealed and Figure 7 shows the longitudinal grinding of a rod, which at 1250 ° C for 150 min. was annealed.
  • the Sn has a grain-refining and grain-stabilizing effect. There was no significant change in hardness and grain size at 100 min and at 150 min annealing time.
  • a pure Nb block (sample 1) was produced from pressed Nb chips, so that comparing the annealing temperatures with the degree of recrystallization and the hardness, the conditions could be compared very well.
  • the pure Nb reference block was forged at 850 ° C, turned and cold rolled with an approx. 10 mm rolled profile.
  • Figure 8 shows a longitudinal section of a rod made of the pure Nb block, which at 100 ° C for 10 min. was completely recrystallized.
  • Figure 9 shows two different areas of a longitudinal section of a rod made of a pure Nb block that at 1250 ° C for 150 min. was completely recrystallized, namely a fine-grained area (top) and a coarser-grained area (bottom). The fine-grained area is already extremely coarse-grained with a grain size of ASTM # 2 to 3 (ASTM standard E 112).
  • Table 2 The results of the tests are summarized again in the following Table 2: Nb alloy Annealing temperature / annealing time Hardness [HV] Grain size Nb 850 ° C / 100 min.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Superconductors And Manufacturing Methods Therefor (AREA)
EP18204539.3A 2018-11-06 2018-11-06 Alliage de niobium-étain et son procédé de fabrication Withdrawn EP3650568A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP18204539.3A EP3650568A1 (fr) 2018-11-06 2018-11-06 Alliage de niobium-étain et son procédé de fabrication

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP18204539.3A EP3650568A1 (fr) 2018-11-06 2018-11-06 Alliage de niobium-étain et son procédé de fabrication

Publications (1)

Publication Number Publication Date
EP3650568A1 true EP3650568A1 (fr) 2020-05-13

Family

ID=64267482

Family Applications (1)

Application Number Title Priority Date Filing Date
EP18204539.3A Withdrawn EP3650568A1 (fr) 2018-11-06 2018-11-06 Alliage de niobium-étain et son procédé de fabrication

Country Status (1)

Country Link
EP (1) EP3650568A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117265617A (zh) * 2023-11-16 2023-12-22 西安聚能超导线材科技有限公司 一种阻隔层制备方法、阻隔层及铌三锡超导线材
CN119242982A (zh) * 2024-12-06 2025-01-03 陕西斯瑞新材料股份有限公司 一种铜铬铌合金、制备方法及真空灭弧室

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4055887A (en) 1975-03-26 1977-11-01 Bbc Brown Boveri & Company Limited Method for producing a stabilized electrical superconductor
JP2001176345A (ja) 1999-12-21 2001-06-29 Japan Magnet Technol Kk 複合体及びＮｂ３Ｓｎ超電導体並びにその製造方法
US20030205106A1 (en) * 2000-08-10 2003-11-06 Showa Denko K.K. Niobium powder, sintered body thereof, and capacitor using the same
JP2004296124A (ja) * 2003-03-25 2004-10-21 Tokai Univ Ｎｂ３Ｓｎ超伝導線材の製造方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4055887A (en) 1975-03-26 1977-11-01 Bbc Brown Boveri & Company Limited Method for producing a stabilized electrical superconductor
JP2001176345A (ja) 1999-12-21 2001-06-29 Japan Magnet Technol Kk 複合体及びＮｂ３Ｓｎ超電導体並びにその製造方法
US20030205106A1 (en) * 2000-08-10 2003-11-06 Showa Denko K.K. Niobium powder, sintered body thereof, and capacitor using the same
JP2004296124A (ja) * 2003-03-25 2004-10-21 Tokai Univ Ｎｂ３Ｓｎ超伝導線材の製造方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
TULEUSHEV A ZH ET AL: "Nanodimensional alloying in metallic films", FIZIKA METALLOV I METALLOVEDENIE (1990), IZDATEL'STVO NAUKA, RU, vol. 97, no. 4, 1 January 2004 (2004-01-01), pages 49 - 57, XP009512023, ISSN: 0015-3230 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117265617A (zh) * 2023-11-16 2023-12-22 西安聚能超导线材科技有限公司 一种阻隔层制备方法、阻隔层及铌三锡超导线材
CN119242982A (zh) * 2024-12-06 2025-01-03 陕西斯瑞新材料股份有限公司 一种铜铬铌合金、制备方法及真空灭弧室

Similar Documents

Publication Publication Date Title
DE69220292T2 (de) Auf TiAl basierende intermetallische Verbindung, Legierungen und Verfahren zur Herstellung dieser
DE1558521C3 (de) Verwendung einer Nickel Chrom Knetlegierung als superplastischer Werk stoff
EP2829624B1 (fr) Matière aluminium ayant une trempe par durcissement structural améliorée
EP2137330B1 (fr) Feuille métallique
AT391435B (de) Verfahren zur herstellung einer odssinterlegierung
WO2000060132A1 (fr) Materiau metallique a base de nickel et son procede de production
DE4241909A1 (fr)
DE3852092T2 (de) Hochfester Titanwerkstoff mit verbesserter Duktilität und Verfahren zur Herstellung dieses Werkstoffs.
EP0369114A1 (fr) Procédé pour la fabrication de barres en alliage de tungstène
EP3644382B1 (fr) Monofilament destiné à la fabrication d'un fil superconducteur contenant du nb3sn, en particulier pour une oxydation interne
DE3700659A1 (de) Feinkoerniger versproedungsfester tantaldraht
DE3019980C2 (de) Verfahren zur Herstellung von Supraleiterdrähten aus mit Kupfer oder Kupferlegierung umgebenen, Niob und Aluminium enthaltenden Multifilamenten
EP3172354B1 (fr) Cible de pulvérisation cathodique à base d'un alliage d'argent
EP3650568A1 (fr) Alliage de niobium-étain et son procédé de fabrication
DE69026658T2 (de) Verfahren zur Herstellung von Titan und Titanlegierungen mit einer feinen gleichachsigen Mikrostruktur
EP1711293B1 (fr) Materiau metallique, son procede de production et son utilisation
WO2018058158A1 (fr) Cible de pulvérisation cathodique
EP0035070B1 (fr) Alliage-mémoire à base d'une solution solide riche en cuivre ou en nickel
EP0679727A2 (fr) Procédé de fabrication d'un alliage de cuivre-nickel-silicium et son utilisation
DE69108723T2 (de) Supraleitender draht.
EP3670691B1 (fr) Alliage de magnesium et son procédé de fabrication
DE102004060900A1 (de) Halbzeug auf Nickelbasis mit Würfeltextur und Verfahren zu seiner Herstellung
DE69706623T2 (de) Kraftstoffbehälter und verfahren zur herstellung des behälters
EP3572539A1 (fr) Procédé de fabrication d'un alliage nbti
DE19709929C1 (de) Hüllrohr eines Brennstabs für ein Siedewasserreaktor-Brennelement und Verfahren zu seiner Herstellung

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20181106

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20201114