WO1996041382A2 - Alliage de niobium et 47 % en poids de titane a addition de fer, et procede de fabrication de fils metalliques supraconducteurs multifilaments - Google Patents

Alliage de niobium et 47 % en poids de titane a addition de fer, et procede de fabrication de fils metalliques supraconducteurs multifilaments Download PDF

Info

Publication number
WO1996041382A2
WO1996041382A2 PCT/US1996/008580 US9608580W WO9641382A2 WO 1996041382 A2 WO1996041382 A2 WO 1996041382A2 US 9608580 W US9608580 W US 9608580W WO 9641382 A2 WO9641382 A2 WO 9641382A2
Authority
WO
WIPO (PCT)
Prior art keywords
ppm
iron
content
tesla
improved
Prior art date
Application number
PCT/US1996/008580
Other languages
English (en)
Other versions
WO1996041382A3 (fr
Inventor
David B. Smathers
Original Assignee
Teledyne Industries, Inc.
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 Teledyne Industries, Inc. filed Critical Teledyne Industries, Inc.
Publication of WO1996041382A2 publication Critical patent/WO1996041382A2/fr
Publication of WO1996041382A3 publication Critical patent/WO1996041382A3/fr

Links

Classifications

    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N60/00—Superconducting devices
    • H10N60/01—Manufacture or treatment
    • H10N60/0156—Manufacture or treatment of devices comprising Nb or an alloy of Nb with one or more of the elements of group IVB, e.g. titanium, zirconium or hafnium

Definitions

  • This invention relates to an improved iron containing niobium 47 weight % titanium superconducting composition and multifilamentary wire made from that composition.
  • the niobium titanium binary alloy is the most commonly applied superconducting material principally because of its ductility.
  • the addition of titanium to niobium greatly increases the upper critical field while only slightly affecting the critical temperature. From zero to 60 weight percent titanium the T c (the critical temperature) varies by only a few degrees Kelvin (9-10.2) while ⁇ 0 H c2 (the upper critical magnetic field strength) goes from 0.2 Tesla to over 11 Tesla at 4.2 K.
  • ⁇ 0 4 ⁇ x 10 "7 henry/meter exactly (permeability of free space) .
  • alpha phase titanium precipitates as well as sub-grain boundaries and other mechanical defects in the material.
  • the magnetic flux quanta (fluxoids) must be "pinned” to prevent motion within the superconductor. Grain boundaries, dislocations, voids and precipitates can act as pinning centers for fluxoids.
  • the alloy is annealed, and quenched, in a single phase region to increase ductility. After significant area reduction, the alloy is aged at intermediate temperature to slowly grow fine alpha titanium precipitates.
  • the composition range 46 to 48 weight percent titanium is the most commonly used alloy at present due to the combination of T c , and ⁇ 0 H c2 and ease of developing the desired distribution (size and number) of alpha titanium precipitates with thermomechanical processing of the alloy in a copper matrix.
  • Some users have chosen Nb44Ti to have a higher T c , and ⁇ 0 H c2 while others have used titanium rich alloys as high as Nb60Ti to increase the amount of titanium available for precipitation, thereby increasing the potential critical current.
  • the titanium content is increased above 55 weight percent the hardness increases significantly making the alloy hard to process in a copper matrix.
  • NbTi alloys were electron beam (E.B.) melted to reduce impurities if fine filament wire was to be produced.
  • the titanium content is hard to control in E. B. melting because the titanium evaporates from the alloy much faster than does the niobium.
  • Vacuum arc melting (V.A.R.) is a superior process for alloy uniformity, but it does not have any ability to reduce impurity levels.
  • the process for refining the niobium involves E.B. melting and effectively reduces all low melting point impurities and interstitial gases (oxygen, nitrogen, carbon, hydrogen, iron, aluminum, etc.) to low levels.
  • the major source of these impurities in the binary alloy is the titanium.
  • the titanium is usually introduced into the alloy in sponge form.
  • Nishimura and Zwicker investigated the effect of iron and niobium on the superconducting properties of titanium and concluded that alloys with high niobium and low iron (less than 3 at.%) showed an increase in T c when annealed in the range 400 to 500 °C. Alloys with low niobium and high iron showed a decrease in T c .
  • Nb 47 wt% Ti composition having an iron content of from greater than 200 to about 2000 ppm has been obtained with improved superconducting properties.
  • Preferred compositions have Ti contents from about 46 to 48 wt %, iron contents from about 500 to 700 ppm, and oxygen contents from about 400 to 700 ppm.
  • Another preferred composition for use in energy storage and MRI has a Ti content from 52 to 55 wt %, an iron content from about 500 to about 1000 ppm, and an oxygen content of from about 350 to 500 ppm.
  • the composition has the ability to develop a fine, distributed ribbon shaped precipitate morphology while increasing the upper critical field. This permits the flow of high critical current density in the 5 to 10 Tesla range at 4.2
  • Multifilamentary wires can be made of these compositions with superior results. They can be used to make a superconducting product having about the same critical current properties at 5 Tesla as products made with less than 200 ppm iron and with an improved upper critical field strength and an improved critical current value at all fields above 5 Tesla as compared to the lower iron containing compositions. Preferable compositions have an upper critical field strength which is at least 0.25
  • Fig. 1 is a graph of the critical current density at 5 Tesla as a function of engineering strain after the Fourth heat treatment.
  • Fig. 2 is a graph of the critical current density at 7 Tesla as a function of engineering strain after the Fourth heat treatment.
  • Fig. 3 is a graph of the critical current density at 8 Tesla as a function of engineering strain after the Fourth heat treatment.
  • Fig. 4 is a graph of critical current density as a function of field for F-D and F-A.
  • Fig. 5 is a graph of critical current density as a function of field for F-D and F-B.
  • Fig. 6 is a graph of the normalized flux pinning force curves for all the F-billets for an engineering strain of 3.5 on a applied field basis.
  • Fig. 7 is a graph of the normalized flux pinning force curves for all the F-billets for an engineering strain of 3.5 on reduced field basis.
  • Nb 47 Ti alloys which were made for superconducting uses had the iron content reduced to below 200 ppm.
  • the compositions including those in ppm, are given on a weight basis and not an atomic basis. Specifications for such materials as set forth in Table 1 have this limitation.
  • Providing for these low iron content alloys increases the cost of the titanium for making the alloy.
  • More expensive titanium reactors are required which can not be made of steel and which must be made of costly low iron containing materials.
  • Second, special pure reactant materials must be used to make sure that the iron content is very low.
  • the alloy compositions of the present invention where the iron content is from 200 ppm to about 2000 ppm and, more preferably, from 450 ppm to about 700 ppm it has been found that not only are the alloys of these compositions capable of superconducting use, but that they have superior properties in the high field strength range and the alloys of these compositions are no harder than conventional alloys of compositions with the lower iron content.
  • the iron content of the titanium sponge is no longer a limiting factor and lower cost titanium sponge can be used.
  • the preferred compositions for high energy physics dipoles and other high field applications will be Nb 46-48 Ti, 500 to 700 ppm Fe and 400-600 ppm oxygen.' This increases the high field J c and lowers the low field J_. This is a better combination for dipole magnets because it will have a lower magnetic hysteresis since the low field J c dominates the hysteresis.
  • An especially preferred alloy composition for use in energy storage and MRI applications has a Ti content of from 52 to 55 wt %, an iron content from about 500 to about 1000 ppm, and an oxygen content of from about 350 to 500 ppm.
  • These compositions can be made into superconductor products having an increased J c at 2 Tesla over a low iron containing version. The iron would allow more and finer precipitates in the high titanium alloy increasing the ability to pin flux and therefore carry more critical current density relative to the low iron material of the same Ti content.
  • the wire has the capacity to pass a larger current, then it can be made of a smaller diameter than other conventional wires.
  • the first is cost. For a given length of wire there will be less material present with the smaller diameter wire which will reduce the cost of the wire. Second, there will be a lower operating cost. These superconductors must be maintained at very low temperatures to operate effectively. Liquid helium is the coolant normally used. Unfortunately, it has a low heat capacity. For every additional cubic centimeter of wire to be cooled, there will be more liquid helium required to keep it cold. Thus, the smaller the diameter for the wire, the less mass it will have and the less liquid helium that will be needed to keep it cold during operation.
  • the third advantage results from the use of smaller wire. As the wire diameter is reduced and electromagnet winding volume becomes more compact and efficient which additionally reduces the amount of wire and, therefore, stresses and cold mass required to generate a given field strength over a given volume.
  • a niobium barrier is included around the NbTi filament to protect the filament from the copper matrix during the aging heat treatments when the matrix is copper.
  • a matrix of copper-silicon reduces the formation of Ti 2 Cu and the niobium barrier can be eliminated.
  • Other choices for the matrix material could be copper-manganese, copper-nickel and aluminum.
  • the basic wire structure would be multiple individual filaments of the NbTi(Fe) alloy in a matrix of any of the above materials and the filament may or may not be completely surrounded by a niobium barrier of up to 10 % of the filament cross sectional area.
  • the wire can be made by many routes known in the art. Once the drawing process has commenced, thermal treatments will be performed at regular strain intervals.
  • the iron may allow the spacing of these treatments to be reduced.
  • the number and length of these treatments may be 1 to 6 times and from 10 to 120 hours each.
  • a conventional treatment would be 4 heat treatments at 375 °C for 40 hours each, spaced at nominally equal strain intervals.
  • the temperature of the aging heat treatment may be from 350 to 474 °C.
  • a further use of these higher iron containing compositions can be to reduce the strain needed after the last heat treatment to achieve the desired J.. This can be a useful result if large monolithic conductors are desired.
  • Nb 47 Ti is meant to cover those superconducting compositions having about 47 wt % Nb and balance Ti. These composition can typically vary over the range of about 44 to 55 wt % Ti.
  • niobium can be obtained commercially from Teledyne Wah Chang, Cabot, CBMM as electron beam refined pure niobium ingot.
  • the titanium can be obtained from Oregon Metallurgical Co. as Ore Met Premium Grade OMC 2060 as well as from TiMet and Sumitomo.
  • Nb 47 Ti alloys having a higher iron content according to the invention are compared with conventional Nb 47 Ti alloys having lower iron contents.
  • Example 2 This example describes the production of billets and wires.
  • Small F-Billets (multi-filament NbTi in copper) were made and processed into wire with standard NbTi heat treatments.
  • the ingots were first machined to 7.23 inches and extruded to a rod having a 2.1 inch diameter.
  • the bare 2.1 inch rod was then drawn to a 0.221 inch rod.
  • the F-Billets were constructed by inserting these 0.221 inch NbTi rods into hexagonal outer shaped, round holed copper tubes of the same length and stacking the hexagonal tubes into a round copper can having a diameter of 3.37 inches.
  • the billets were stacked with one solid copper hexagonal element in unique positions so that samples could be sorted out metallographically.
  • the assembly had a copper lid electron beam welded on to each end to provide a hermetic, vacuum contained seal.
  • the assembly is heated and extruded to 0.9 inch in diameter with a direct extrusion press.
  • the press used in this example was a 1200 ton capacity press manufactured by Baldwin.
  • the extruded rods were processed to wires with four intermediate heat treatments of 40 hours at 375 °C spaced at engineering strain intervals of 1.1.
  • Critical current test samples were taken at engineering strains of 2.5, 3, 3.5, 4, 4.5 and 5 after the fourth heat treatment.
  • F-Billets are referred to as F-A, F-B, F-C and F-D depending on which ingot A-D was used.
  • This example describes the measurement of hardness values for the wires.
  • This example illustrates the critical current density as a function of applied field.
  • Figures 1-3 show the J c as a function of drawing strain after the last heat treatment for applied fields of 5, 7 and 8 Tesla.
  • This type of analysis offers insight into the relative size and distribution of pinning centers in the wire. To be effective the pinning centers must be on the order of 5 nanometers thick and there must be many of them.
  • the standard wires using heats C and D have well-known microstructures.
  • the data in the figures clearly show that J c begins to develop earlier in the high iron heats A and B. This could signify that a finer precipitation has occurred since the precipitates appear to be nearing their optimum size at lower area reductions.
  • the surprising result, then, is that J. doesn't fall off sooner and that both the high and the low iron materials peak at the same strain.
  • the critical current density was measured at various applied fields for wires made of Ingot B having the higher iron content according to the invention and Ingot D which is the conventional low iron containing wire. The results are plotted in Fig. 5. At a field of about 5 Tesla the two wires have about the same critical current density, J c . However, at the higher fields of from 6.5 to 9 Tesla where one would prefer to operate to produce effective electromagnets for advanced devices, the wires made of Ingot B according to the present invention have the higher critical current densities. This is a surprising and unexpectedly beneficial property since wire made of this unique composition can carry more current that the conventional low iron containing wire.
  • the result observed on the present examples confirmed the speculation generated by the Figures 1-3.
  • the high iron heats A and B show finer, more spherical precipitates than the low iron heats C and D and a lower overall precipitated volume. These finer, more spherical precipitates will develop into ribbons of the right shape and size for strong flux pinning at a lower strain and at high strains may become too small to effectively pin.
  • Figures 4 and 5 compare the critical current as a function of field for F-D with F-A and F-B, respectively.
  • the low to high field critical current development is different with the higher Fe content.
  • the maximum J c in the high Fe billets at 5 Tesla was identical to the low Fe billets. Note, in this comparison, that high Fe was associated with low oxygen.
  • the billet F-B developed the highest J c of all the wires and at 8 Tesla in Fig. 3
  • both the billets F-A and F-B had higher J c than the low Fe billets even when the composition of Ingot A Example 1 failed to develop the expected 5 Tesla number and had low 'n'-values.
  • the peak 7 Tesla result in Fig. 2 for the F-B billet was 4% higher and developed at lower strain than the best result from billet F-D.
  • the peak 8 Tesla result in Fig. 3 for F-B was 8% higher than that for F-D, yet they both had identical 5 Tesla results.
  • Example 5 This example describes the flux pinning strength for the wires and demonstrates the higher upper critical field values obtained for the higher iron containing materials. Normalized flux pinning curves were made for all the F-billets for an engineering strain of 3.5. The normalized pinning force is determined by multiplying the critical current density by the magnetic field and dividing by the maximum achieved value. This format is useful for comparing the shapes of flux pinning curves which give insight about the microscopic structures producing the flux pinning.
  • the wires made of the higher iron content according to the invention have about 1/3 Tesla higher B c2 * value than the values for the conventional low iron compositions. Since the higher iron containing wires have a higher upper critical field the wires have more potential to carry higher currents at these higher fields relative to the wire with lower B c2 * values.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Superconductors And Manufacturing Methods Therefor (AREA)

Abstract

Cette invention concerne des compositions de niobium 47 % en poids de titane ayant une teneur accrue en fer comprise entre 200 et 2000 p.p.m, lesdites compositions présentant des caractéristiques supraconductrices améliorées. En ce qui concerne les applications de physique à haute énergie, les niveaux préférés de concentration varient entre environ 46 et 48 % en poids de titane, entre 500 et 700 p.p.m environ de fer et entre 400 et 700 p.p.m environ d'oxygène, et en ce qui concerne les applications d'accumulation de l'énergie et d'imagerie par résonance magnétique (IRM), ces niveaux préférés de concentration varient entre environ 52 et 55 % en poids de titane, entre 500 et 1000 p.p.m environ de fer et entre 350 et 500 p.p.m environ d'oxygène. Ces compositions forment une structure fine et répartie de précipités en forme de rubans lorsqu'elles servent à la fabrication de fils métalliques, ce qui accroît le champ critique supérieur. Ceci permet le passage de fortes densités de courant critique, dans la gamme d'induction de 5 à 10 Tesla et à 4.2° Kelvin. Les fils métalliques multifilaments fabriqués à partir de ces compositions forment des produits supraconducteurs présentant les mêmes caractéristiques de courant critique à 5 Tesla que des produits comportant une teneur en fer inférieure à 200 p.p.m. Ces produits possèdent cependant une plus grande densité de champ critique supérieur et une plus grande valeur de courant critique pour tous les champs au-dessus de 5 Tesla par rapport aux compositions à teneur en fer inférieure. Les compositions préférées ont une densité de champ critique supérieur qui est supérieure, d'au moins 0,25 Tesla, à celle des compositions à faible teneur en fer.
PCT/US1996/008580 1995-06-07 1996-06-05 Alliage de niobium et 47 % en poids de titane a addition de fer, et procede de fabrication de fils metalliques supraconducteurs multifilaments WO1996041382A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US47584095A 1995-06-07 1995-06-07
US08/475,840 1995-06-07

Publications (2)

Publication Number Publication Date
WO1996041382A2 true WO1996041382A2 (fr) 1996-12-19
WO1996041382A3 WO1996041382A3 (fr) 1997-01-30

Family

ID=23889371

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1996/008580 WO1996041382A2 (fr) 1995-06-07 1996-06-05 Alliage de niobium et 47 % en poids de titane a addition de fer, et procede de fabrication de fils metalliques supraconducteurs multifilaments

Country Status (1)

Country Link
WO (1) WO1996041382A2 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2019113528A (ja) * 2017-12-21 2019-07-11 ニヴァロックス−ファー ソシエテ アノニム 固定式時計又は携行式時計のムーブメントのための渦巻き状のばね及びその製造方法
EP3422115B1 (fr) 2017-06-26 2021-08-04 Nivarox-FAR S.A. Ressort spiralé d'horlogerie

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5374320A (en) * 1992-06-19 1994-12-20 The Furukawa Electric Co., Ltd. Nb-Ti alloy type superconducting wire

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0192338A (ja) * 1987-10-01 1989-04-11 Nippon Soda Co Ltd 高純度ニオブチタン合金スポンジ及びその製法

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5374320A (en) * 1992-06-19 1994-12-20 The Furukawa Electric Co., Ltd. Nb-Ti alloy type superconducting wire

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
DATABASE WPI Section Ch, Week 8920 Derwent Publications Ltd., London, GB; Class L03, AN 89-148354 XP002018487 & JP 01 092 338 A (NIPPON SODA KK) , 11 April 1989 *
INTERNATIONAL SYMPOSIA ON ADVANCED MATERIALS AND TECHNOLOGY FOR THE 21ST CENTURY. JIM 95 FALL ANNUAL MEETING, HI, USA, 1995, vol. 37, no. 3, ISSN 0916-1821, MATERIALS TRANSACTIONS, JIM, MARCH 1996, JAPAN INST. METALS, JAPAN, pages 519-526, XP000609396 SMATHERS D B ET AL: "Improved niobium 47 weight % titanium composition by iron addition" *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3422115B1 (fr) 2017-06-26 2021-08-04 Nivarox-FAR S.A. Ressort spiralé d'horlogerie
JP2019113528A (ja) * 2017-12-21 2019-07-11 ニヴァロックス−ファー ソシエテ アノニム 固定式時計又は携行式時計のムーブメントのための渦巻き状のばね及びその製造方法
JP2020187134A (ja) * 2017-12-21 2020-11-19 ニヴァロックス−ファー ソシエテ アノニム 固定式時計又は携行式時計のムーブメントのための渦巻き状のばね及びその製造方法

Also Published As

Publication number Publication date
WO1996041382A3 (fr) 1997-01-30

Similar Documents

Publication Publication Date Title
Flükiger et al. Microstructure, composition and critical current density of superconducting Nb3Sn wires
Bevk et al. Anomalous increase in strength of in situ formed Cu‐Nb multifilamentary composites
Snoeck et al. Microstructural studies of in situ produced filamentary Cu/Nb wires
Godeke et al. State of the art powder-in-tube niobium–tin superconductors
US3215569A (en) Method for increasing the critical current of superconducting alloys
Pike et al. Site occupancies, point defect concentrations, and solid solution hardening in B2 (Ni, Fe) Al
US20030045433A1 (en) Nb3Sn-system superconductive wire
Adamczyk et al. Superconducting Properties Comparison of SiC Doped Multifilamentary ${\rm MgB} _ {2} $ Wires of Various Sheaths (Cu, Monel, Glidcop) After High Pressure HIP Treatment
WO1996041382A2 (fr) Alliage de niobium et 47 % en poids de titane a addition de fer, et procede de fabrication de fils metalliques supraconducteurs multifilaments
US4508578A (en) Method of manufacturing fine filamentary Nb-Ti based alloy superconducting wire
Abdyukhanov et al. Superconducting Properties of Nb 3 Sn Superconductors, Doped With Ti, Zr and Ti, Ti and Ta
Hishinuma et al. Changes of superconducting properties due to the unidirectional tensile deformation on bronze-processed Nb3Sn multifilamentary wires using various Cu–Sn–Zn ternary alloy matrices
Niu et al. Cryogenic temperature properties and secondary phase characterization of CuCrZr composites
Hishinuma et al. Mechanical Strength Evaluation of the Internal Matrix Reinforced Nb 3 Sn Multifilamentary Wires Using Cu–Sn–In Ternary Alloy Matrix
Abdyukhanov et al. Production of ${\rm Nb} _ {3}{\rm Sn} $ Bronze Route Strands With High Critical Current and Their Study
Popova et al. Effect of annealing and doping with Zr on the structure and properties of in situ Cu–Nb composite wire
Heussner et al. Artificial pinning center Nb-Ti superconductors with alloyed Nb pins
Kamata et al. High-Field Current-Carrying Capacities of ‘Titanium Bronze’Processed Multifilamentary Nb 3 Sn Conductors with Pure and Alloy Cores
US3303065A (en) Superocnductive alloy members
Balachandran et al. High-Strength Cu–Ta–W Composite
Chernyi et al. Current characteristics and microstructure in a multifilamentary Nb-37Ti-22Ta superconductor
Ullrich et al. High temperature deformation of Bridgman melt-textured YBCO
Kikuchi et al. Nb/sub 3/(Al, Ge) multifilamentary wires made by the rapidly-heating/quenching process
JP2011214124A (ja) 合金超伝導体生成方法、及び合金超伝導体
Kurahashi et al. Effect of third-element additions on the upper critical field of bronze-processed Nb/sub 3/Sn

Legal Events

Date Code Title Description
AL Designated countries for regional patents

Kind code of ref document: A2

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE

AL Designated countries for regional patents

Kind code of ref document: A3

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE

121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase