Development of Ag-sheathed Bi(2223) superconducting wires and coils

Ueyama, M.; Ohkura, K.; Hayashi, Kazuhiko; Kobayashi, Shinichi; Muranaka, K.; Hikata, Takeshi; Saga, Nobuhiro; Hahakura, S.; Sato, K.

doi:10.1016/0921-4534(95)00827-6

Cited by 6 publications

(9 citation statements)

References 8 publications

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“…In other conductors transport currents of 60 A at 77 K have been reached. At 4 K the J, value is, increased to 100 kA/cm2 representing an increase by a factor 6 which is in accordance with references [2,5].…”

Section: Field and Temperature Dependency Of Critical Currentssupporting

confidence: 87%

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Development of twisted Bi-2212 and Bi-2223 powder in tube conductors for AC applications

Herrmann

Beghin

Duperray

et al. 1997

IEEE Trans. Appl. Supercond.

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Within Alcatel Alsthom Group, Alcatel Cable and Alcatel Alsthom Recherche Center have undertaken a HTc research program, with support from EDF : the aim was to develop conductors suitable for ac applications, where major market opportunities are expected. For ac applications at 50 Hz low ac loss conductors with a resistive matrix material and a twist length of the superconducting filaments of less than 10" are required. Bi-2223 and Bi-2212 conductors are fabricated up to lengths of 200 m of 64 filaments tape by the patented rectangular Alcatel Alsthom route. Recently Bi-2212 conductors for 20 K applications have been tested at liquid helium temperatures. Different Bi-2212 conductors with a twist length of 7 to 9 mm, with a silver-alloy matrix and a cross section of 0.5 mm x 3 mm have been realised. In such conductors transport currents of 400-500 A have been measured at 4 K in self fields with a very good reproducibility. The engineering current density in the wire has reached the threshold value of Je = 30'000 A/cm2. The superconducting volume fraction of the conductor is 18 % which results in a critical current density in the superconductor of Jc = 170'000 A/cm2. At liquid nitrogen temperature transport currents of 18 A are carried in this conductor. For this temperature range the development of a Bi-2223 conductor is under progress. For instance, different untwisted conductors with transport currents up to Ic(77K) = 60 A and critical current densities up to are realised.

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Section: Field and Temperature Dependency Of Critical Currentssupporting

confidence: 87%

“…Hitachi Sumitomo [2] Bi-2223/Ag: 300 kA/cm2, Alcatel Alsthom Bi-2223/Ag: 100 kA/cm2. Concerning the Bi-2212 conductor the initial field dependency of the Alcatel conductor is more severe than in the Hitachi conductor.…”

Section: Field and Temperature Dependency Of Critical Currentsmentioning

confidence: 99%

Development of twisted Bi-2212 and Bi-2223 powder in tube conductors for AC applications

Herrmann

Beghin

Duperray

et al. 1997

IEEE Trans. Appl. Supercond.

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“…Up to 20 m long monofilamentary tapes have been prepared without major problems [46]. However, there is a strong limitation to their industrial application: monofilamentary Bi,Pb(2223) tapes show irreversible damage after tensile stresses as low as 0.2% [44,45], while multifilamentary tapes withstand considerably higher stresses without damage, up to 0.6% [44,45]. Nevertheless, monofilamentary tapes are useful for investigations of the formation conditions and for the determination of physical properties, e.g.…”

Section: The Powder-in-tube Methodmentioning

confidence: 99%

Phase formation and critical current density in Bi,Pb(2223) tapes

Flükiger

Grasso

Grivel

et al. 1997

Supercond. Sci. Technol.

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The various fabrication and reaction processes leading to multifilamentary Bi,Pb(2223) tapes with high transport are described. In air, the Bi,Pb(2223) phase in pressed powders is found to be formed by nucleation, following the complete decomposition of the Bi,Pb(2212) intermediate phase. In this work, the precise formation conditions of the Pb-free phase Bi(2223) are described for the first time. It is shown that the presence of Pb leads to a lowering of the melting temperature from 879 to and of that of the `transient liquid' . The latter is formed after decomposition of the 2-layer compound and is necessary to the formation of the 3-layer compound. Thus Pb is found to have no influence on the formation mechanism of the 3-layer compound, which always starts by a nucleation process. Nucleation processes are also found to occur in the first phase of reaction inside Ag sheathed tapes, intercalation being possible at later stages. The highest values of the critical current density in Bi,Pb(2223) tapes reported at the present day are compared, taking into account the analysed tape lengths. The variation of in mono- and multifilamentary Bi,Pb(2223) tapes as a function of the applied magnetic field at 77 and at 4.2 K is described. A new process including deformation by a four-roll machine is presented, and the distribution of inside various tape configurations with similar critical current densities is analysed: for monofilamentary tapes, a maximum of is found at the borders, the ratio being 2.4, while for conventional multifilamentary tapes the maximum is found at the tape centre (, ratio 1.6). For the new four-rolled tapes, a ratio of only 1.1 was measured, indicating a more homogeneous current distribution. In order to lower the AC losses due to the highly conductive Ag matrix, the new concept of `oxide barriers' is introduced. A barrier of surrounds each filament, thus leading to an enhanced radial resistivity, which in turn reduces AC losses. Finally, the current transport mechanism inside Bi,Pb(2223) tapes and the various current limiting mechanisms are discussed.

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“…Beginning with the discovery of high-temperature superconductivity in perovskite systems containing oxygen by Bednorz and Muller [1,2], the literature on this topic has become a veritable avalanche, as works on fabrication of metal [3,4,5,6,7,8,9,10,11,12,13,14] and polymer [15,16,17,18,19,20,21,22,23,24,25,26] binder composites of various geometries possessing SC properties were undertaken, alongside with fundamental research.…”

Section: Introductionmentioning

confidence: 99%

“…It must be noted that the coke formed after incineration has a negative impact on SC properties. Also known are polymer-ceramic compositions designed to protect high-temperature super-conductors against humidity [13,14]. …”

Section: Introductionmentioning

confidence: 99%

Intercalated Nanocomposites Based on High-Temperature Superconducting Ceramics and Their Properties

2009

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High temperature superconducting (SC) nanocomposites based on SC ceramics and various polymeric binders were prepared. Regardless of the size of the ceramics’ grains, the increase of their amount leads to an increase of resistance to rupture and modulus and a decrease in limiting deformation, whereas an increase in the average ceramic grain size worsens resistance properties. The SC, thermo-chemical, mechanical and dynamic-mechanical properties of the samples were investigated. Superconducting properties of the polymer ceramic nanocomposites are explained by intercalation of macromolecule fragments into the interstitial layer of the ceramics’ grains. This phenomenon leads to a change in the morphological structure of the superconducting nanocomposites.

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Development of Ag-sheathed Bi(2223) superconducting wires and coils

Cited by 6 publications

References 8 publications

Development of twisted Bi-2212 and Bi-2223 powder in tube conductors for AC applications

Development of twisted Bi-2212 and Bi-2223 powder in tube conductors for AC applications

Phase formation and critical current density in Bi,Pb(2223) tapes

Intercalated Nanocomposites Based on High-Temperature Superconducting Ceramics and Their Properties

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