International round robin test for tensile testing HTS wires at cryogenic temperatures

Abstract

Within the framework for establishing standards of test methods for superconducting technical wires, various standards have been issued by the International Electrotechnical Commission (IEC) (standard documents IEC 61788-1 to -20). Following the successful round robin test (RRT) for tensile testing REBCO wires at room temperature (Osamura K et al 2014 Supercond. Sci. Technol. 27 085009), this effort is extended to tensile test HTS wires at cryogenic temperatures and is coordinated by the CryoMaK lab at Karlsruhe Institute of Technology. Five different commercially available REBCO wires from five different manufacturers and one BiSCCO wire from another supplier were provided by the Versailles Project on Advanced Materials and Standards (http://vamas.org) for testing. Samples were distributed between eight participating labs from five different countries for testing according to the specified guidelines. After the test results were delivered by all participants, the data were evaluated with statistical tools to investigate the main source of scatter and its magnitude in the test results. The final goal of the RRT is issuing an ISO/ IEC standard for a cryogenic temperature tensile test for REBCO wires. In this report the results of the RRT for tensile testing REBCO wires at cryogenic temperatures are presented and discussed.

Recent development and mass production of high J e 2G-HTS tapes by using thin hastelloy substrate at Shanghai Superconductor Technology

“…Then, the typical I-V curves were collected as usual. The axial tension test is operated with a Nyilas type extensometer at liquid nitrogen temperature according to the guideline described in the reference [20]. The proof strength R p0.2_0 is determined from 0.2% offset strain.…”

Establishing a test procedure for evaluating the electromechanical properties of practical REBCO coated conductor tapes by the uniaxial tension test at 77 K

“…Standardization activities such as measuring critical current, I c [7,8], and retained I c after the double bending test [9], and the tensile test at room temperature (RT) [10] have been carried out for establishing measurement standards of HTS wires/tapes. An international round robin test (RRT) is currently underway to establish a tensile test method for HTS wires at cryogenic temperatures [11]. Industry has a strong need for standardization of the electromechanical properties of CC tapes.…”