Characteristic responses of critical current in REBCO coated conductor tapes under tensile/compressive bending strains at 77 K

  • Received : 2018.12.11
  • Accepted : 2018.12.21
  • Published : 2018.12.31


When REBCO coated conductors (CCs) are applied to superconducting devices such as coils and magnets, they are subjected to deformation in various modes such as compression/tension bending, uniaxial/transverse tension and torsion. Despite outstanding performances by REBCO CC tapes, their electromechanical properties have been evaluated primarily under uniaxial tension, therefore data about the critical current ($I_c$) response in the compressive strain region are lacking. In this study, the characteristic responses of $I_c$ in REBCO CC tapes under bending strains in the range from tensile to compressive were evaluated. The springboard bending beam was used, wherein the CC tape sample was soldered onto the surface of the springboard. A Goldacker-type bending test rig, which lacks a support holding the sample during testing, was used as a comparator. Degradation in $I_c$ behaviors, including strain sensitivity, in differently processed REBCO CC tapes were examined based on the test rig used.


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Fig. 1. Schematic structures of (a) Sample 1 and (b) Samples 2 and 3.

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Fig. 2. Appearance of the springboard assembly mounted on the testing machine for electromechanical property measurements at 77 K.

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Fig. 3. Schematic cross-section of the springboard bending beam with the CC tape sample attached.

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Fig. 4. Behaviors of Ic/Ic0 against bending strains in various GdBCO CC tapes, obtained using (a) a springboard bending beam and (b) a Goldacker-type bending test rig.

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Fig. 5. Normalized critical current, Ic/Icmax, in various CC tapes, obtained using (a) a springboard bending beam and (b) a Goldacker-type bending test rig.


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Supported by : National Research Foundation of Korea, Korea Electric Power Corporation


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