应变方式对Bi-2223/Ag超导带材中微裂纹的形成及临界电流的影响  

Effect of Strain Ways on the Micro-Crack Formation and Critical Current of Bi-2223/Ag Superconducting Tapes

作　　者：陈兴品[1] 余晓伟[1] 尚都[1] 郑军 刘庆[1] 

机构地区：[1]重庆大学,重庆400030 [2]武汉船用电力推进装置研究所,武汉湖北430064

出　　处：《稀有金属材料与工程》2012年第7期1206-1210,共5页Rare Metal Materials and Engineering

基　　金：国家"863"高技术研究发展计划(2008AA030601;2009AA03Z202);中央高校基本科研业务费科研专项"研究生科技创新基金"(CDJXS10131156)

摘　　要：对比研究了拉伸、弯曲和压缩3种应变方式对Bi-2223/Ag高温超导带材中微裂纹的形成以及临界电流的影响。实验结果表明:带材的临界应变值在不同的应变方式作用下表现出明显的差异。同时,超导芯中裂纹的扩展途径也有所不同,弯曲时裂纹从带材上表面向内扩展,而拉伸时裂纹的产生则具有随机性。重点讨论了带材内部微裂纹的产生机理,实验发现,带材在拉伸过程中产生轧向裂纹和横向裂纹,而在压缩过程中以轧向裂纹为主,横向裂纹较少。正是这两种裂纹的交互作用导致带材临界电流的降低。The effects of different strain ways （tension, bend and compression） on the formation and propagation of micro-cracks and critical current of Bi-2223/Ag superconducting tapes were studied. The results show an obviously differences on the critical strain values of the tapes under various strain ways are presented. Moreover, the propagation ways of the micro-cracks in the superconductor filaments are quite different： the micro-cracks form at the surface and then spread to the center in the bending samples, while the formation of the cracks are at random in the tensile samples. The formation mechanism of micro-cracks in the filaments was mainly discussed. It is found that multitudes of transversal and rolling direction micro-cracks form under tensile deformation. However, predominantly rolling direction micro-cracks and little transversal micro-cracks are found under compressive deformation. It is the interaction of the above mentioned two types of the micro-cracks that leads the degradation of Ic of the tapes

关 键 词：Bi-2223/Ag高温超导带材 应变方式 力学性能 裂纹形成 临界电流 

分 类 号：TM26[一般工业技术—材料科学与工程]