Differences in applied axial strain andIcdegradation of Bi(2223)/Ag tapes

Kòváč, Pavol; Bukva, P

doi:10.1088/0953-2048/14/4/102

Cited by 22 publications

(21 citation statements)

References 21 publications

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“…A tensile load up to 1000 N applied to the specimen is transferred from sliding motion of the pusher along the bevel edge of the tension arm [18]. This allows the specimen to contract freely during cooling down to 4.2 K, which is not possible for U-shape or Walter-spiral spring systems having the sample soldered to sample holder [19,20]. The present system makes it possible to obtain σ (ε) and I c (ε) characteristics of tested sample at the same time, but it is only applicable for tension [18].…”

Section: The Tensile Test Systemmentioning

confidence: 99%

Behaviour of filamentary MgB₂wires subjected to tensile stress at 4.2 K

Kòváč

Kopera

Melíšek

et al. 2013

Supercond. Sci. Technol.

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Different filamentary MgB 2 wires have been subjected to tensile stress at 4.2 K. Stress-strain and critical current versus stress and strain characteristics of wires differing by filament architecture, sheath materials, deformation and heat treatment were measured and compared. It was found that the linear increase of critical current due to the pre-compression effect (ranging from 5% up to ≈20%) is affected by thermal expansion and the strength of used metallic sheaths. The values of irreversible strain ε irr and stress σ irr depend dominantly on the applied outer sheath and its final heat treatment conditions. Consequently, the strain-tolerance of MgB 2 wires is influenced by several parameters and it is difficult to see a clear relation between I c (ε) and σ (ε) characteristics. The lowest ε irr was measured for Monel sheathed wires (0.3-0.6%), medium for GlidCop R sheath (0.48-0.6%), and the highest ε irr = 0.6-0.9% were obtained for MgB 2 wires reinforced by the stainless steel 316L annealed at temperature between 600 and 800 • C. The highest ε irr = 0.9% and σ irr = 900 MPa were measured for the work-hardened steel, which is not considerably softened by the heat treatment at 600 • C/2.5 h.

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Section: The Tensile Test Systemmentioning

confidence: 99%

Behaviour of filamentary MgB₂wires subjected to tensile stress at 4.2 K

Kòváč

Kopera

Melíšek

et al. 2013

Supercond. Sci. Technol.

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“…A REVERSIBLE strain effect has been measured in many high-temperature superconductors, where the critical current I c and the flux pinning force reversibly change with the strain in Bi 2 Sr 2 CaCu 2 O x (Bi-2212) wires and tapes [1], [2], Bi 2 Sr 2 Ca 2 Cu 3 O x (Bi-2223) tapes [3]- [6], and rare earth (RE)-Ba 2 Cu 3 O 7−δ (RE = Y, Gd, Dy, Sm, etc. ; REBCO) coated conductors [7]- [14].…”

Section: Introductionmentioning

confidence: 99%

Correlation Between In-Plane Grain Orientation and the Reversible Strain Effect on Flux Pinning in RE-$\hbox{Ba}_{2}\hbox{Cu}_{3}\hbox{O}_{7 - \delta}$ Coated Conductors

Laan

Douglas

Goodrich

et al. 2012

IEEE Trans. Appl. Supercond.

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The uniaxial pressure dependence of the critical temperature causes a reversible effect of strain on the critical current density and the flux pinning strength in many high-temperature superconductors. Recent experiments on patterned coated conductor bridges have shown that the anisotropic nature of the pressure dependence of the critical temperature of rare earth (RE)-Ba 2 Cu 3 O 7−δ (REBCO) has a major impact on the performance of coated conductors under strain. The strain effect on the critical current density is most prominent when the strain is along the [100] and [010] directions of the superconducting film, whereas it almost completely disappears when the strain is along [110]. In this paper, we investigate the correlation between the uniaxialpressure dependence of the critical temperature and the reversible strain effect on flux pinning in REBCO coated conductors. We show that axial strain has a large effect on the irreversibility field and the pinning force in coated conductors when the [100] and [010] directions of the superconducting film are aligned along the conductor axis. The magnitude of the strain effect in these conductors largely depends on the angle at which the magnetic field is applied. On the other hand, the critical temperature is not expected to change with the axial strain in coated conductors when the [110] direction is aligned along the conductor axis. Indeed, the irreversibility field and the magnetic field dependence of the pinning force of these conductors are almost independent of the axial strain for all angles at which the magnetic field is applied. The minor strain dependence of the critical current measured in these conductors could be caused by the average in-plane grain misalignment of between 6 • and 8 • , which causes a slight variation in the strain alignment with the axes of the superconducting film. The results confirm that the reversible strain effect in REBCO coated conductors is largely determined by the uniaxial pressure dependence of the critical temperature.

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“…The sample was soldered using a commercial Pb-63% Sn solder, and irreversible degradation occurs at tension strain of 0.57% [17]. A larger ε irr value measured here for the Ni sheathed tape can be attributed partially to an internal reinforcement by the Fe barrier and dominantly by the used U-shaped rig shunting the sample mechanically [1]. Fig.…”

Section: Methodsmentioning

confidence: 62%

“…The most used mechanical test for composite SCs is the tensile test, typically applied at room or at low (cryogenic) temperature. Several types of tensile test devices were used for characterization of composite SCs at variable strains (ε) [1]- [4]. It was shown that, in some cases, the applied measurement setup influences the critical current (I c ) characteristics of the measured sample [1], [2].…”

mentioning

confidence: 99%

“…Several types of tensile test devices were used for characterization of composite SCs at variable strains (ε) [1]- [4]. It was shown that, in some cases, the applied measurement setup influences the critical current (I c ) characteristics of the measured sample [1], [2]. Several authors [3]- [5] measured electromechanical properties of MgB 2 /Fe wires shortly after the MgB 2 compound discovery.…”

mentioning

confidence: 99%

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Tensile and Bending Strain Tolerance of <italic>Ex Situ</italic> MgB2/Ni/Cu Superconductor Tape

Kòváč

Kopera

Melíšek

et al. 2015

IEEE Trans. Appl. Supercond.

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This paper describes the strain tolerance of MgB 2 / Ni/Cu tape produced by Columbus Superconductors subjected to tension and bending stress. A tension test instrument with freestanding sample was used for stress-strain, I c -stress, and I c -strain characteristics at liquid helium temperature. Bending of MgB 2 /Ni/Cu tape to variable diameters was done at room temperature and in two directions: 1) with a Cu strip on the outer surface (Cu out) of a bent sample; and 2) with a Cu strip on the inner side (Cu in). I c -bending strain characteristics were measured at 4.2 K and external field B = 6 T oriented perpendicularly to the sample's width. Obtained results have shown the strain limits, which should not be exceeded during the winding process of superconductor containing brittle MgB 2 filaments.

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Differences in applied axial strain andI_cdegradation of Bi(2223)/Ag tapes

Cited by 22 publications

References 21 publications

Behaviour of filamentary MgB₂wires subjected to tensile stress at 4.2 K

Behaviour of filamentary MgB₂wires subjected to tensile stress at 4.2 K

Correlation Between In-Plane Grain Orientation and the Reversible Strain Effect on Flux Pinning in RE-$\hbox{Ba}_{2}\hbox{Cu}_{3}\hbox{O}_{7 - \delta}$ Coated Conductors

Tensile and Bending Strain Tolerance of <italic>Ex Situ</italic> MgB<sub>2</sub>/Ni/Cu Superconductor Tape

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Differences in applied axial strain andIcdegradation of Bi(2223)/Ag tapes

Cited by 22 publications

References 21 publications

Behaviour of filamentary MgB2wires subjected to tensile stress at 4.2 K

Behaviour of filamentary MgB2wires subjected to tensile stress at 4.2 K

Correlation Between In-Plane Grain Orientation and the Reversible Strain Effect on Flux Pinning in RE-$\hbox{Ba}_{2}\hbox{Cu}_{3}\hbox{O}_{7 - \delta}$ Coated Conductors

Tensile and Bending Strain Tolerance of <italic>Ex Situ</italic> MgB<sub>2</sub>/Ni/Cu Superconductor Tape

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Product

Resources

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Differences in applied axial strain andI_cdegradation of Bi(2223)/Ag tapes

Behaviour of filamentary MgB₂wires subjected to tensile stress at 4.2 K

Behaviour of filamentary MgB₂wires subjected to tensile stress at 4.2 K