Bending tolerance is one of the most fundamental mechanical properties of REBCO coated conductors for application to a superconducting coil. In this study, we investigated critical current degradation of REBCO coated conductors under bending and uniaxial tensile strain at 77 K and self-field with three different kinds of production from SuperPower Inc, Suzhou Advanced Materials Research Institute (SAMRI) and Shanghai Superconductor Technology (STT), respectively. All the tapes showed better bending tolerance under compressive strain than tensile strain, particularly for STT tapes, which showed no Ic degradation in compressive bending strain even with bending radius of 4.5 mm, but a 5% Ic degradation in tensile strain with bending radius of 6–6.5 mm. A uniaxial tensile strain test was also carried out to verify the dependence of Ic under tensile bending strain, the test results showed a good agreement between them. The tensile strain tolerance was 0.28–0.29% for STT tapes, 0.4–0.43% for SAMRI tapes, and 0.5–0.55% for SuperPower tapes.

弯曲公差是用于超导线圈的REBCO涂层导体的最基本机械性能之一。在这项研究中，我们研究了SuperPower公司，苏州先进材料研究院（SAMRI）和上海超导体技术（STT）三种不同生产方式下在77 K和自场下在弯曲和单轴拉伸应变下REBCO涂层导体的临界电流退化）， 分别。所有胶带在压缩应变下均表现出比拉伸应变更好的弯曲耐受性，特别是对于STT胶带，即使在4.5 mm的弯曲半径下，压缩弯曲应变中Ic均没有下降，但Ic却为5％弯曲半径为6–6.5 mm的拉伸应变的退化。还进行了单轴拉伸应变试验，以验证Ic在拉伸弯曲应变下的依赖性，试验结果表明它们之间有很好的一致性。STT磁带的拉伸应变容差为0.28–0.29％，SAMRI磁带为0.4–0.43％，SuperPower磁带为0.5–0.55％。