Ba-122铁基超导带材扭转下临界性能研究

Critical property of Ba-122 Iron-based tapes under torsional

为推动铁基超导带材实用化发展,本文研制出一种在铁基超导带材纯扭转测试装置,分析了7芯Ba_(1-x)K_(x)Fe_(2)As_(2)(Ba-122)带材在扭转应变下临界性能变化。带材临界电流在扭转应变下会出现衰退行为,并且随扭转应变增大而减小。四对电压信号测量结果一致,表明扭转变形均匀。以95%的初始临界电流为临界扭转标准,带材临界扭转角为120°,相应的临界剪切应变为0.86%和临界扭转螺距为240 mm。扭转应力会损伤超导芯,导致带材临界载流性能降低。

In order to promote the practical development of iron-based superconducting tape,a pure torsion test device for iron-based superconducting tape was developed in this paper.The critical properties of 7-filamentary(Ba-122)tape was an⁃alyzed under torsional strain.The critical current of tape decreases under torsional strain and decreases with the increase of tor⁃sional strain.The measurement results of four pairs of voltage signals are consistent,indicating uniform torsion deformation.With 95%initial critical current as the critical torsion standard,the critical torsion angle of the strip is 120°,the corresponding critical shear strain is 0.86%and the critical torsion pitch is 240 mm.The torsional stress can damage the superconducting filamentary and reduce the critical current-carrying performance of the tape.