拉伸应变对Bi-2223银及银合金包套带材临界电流的影响  

Tensile Strain Effects on Critical Current of Ag and Ag Alloy-Sheathed Bi-2223 Superconducting Tapes

作　　者：李成山[1] 吕朝阳[2] 郝清滨[1] 郑会玲[1] 张平祥[1] 

机构地区：[1]西北有色金属研究院,陕西西安710016 [2]东北大学,辽宁沈阳110006

出　　处：《稀有金属材料与工程》2006年第11期1691-1694,共4页Rare Metal Materials and Engineering

摘　　要：研究了Bi-2223带材的应力-应变特征,比较了包套材料、芯丝数目和Ag/超比例对Bi-2223带材不可逆拉伸应变的影响。实验发现,采用高强度的AgMn合金包套材料可提高芯丝的残余压应变,并通过提高Ag/超界面的平整性,减少因为界面不均匀而产生的应力集中,芯丝中微裂纹的出现和扩展将被延迟到更高的应变状态,因此可显著提高带材的不可逆拉应变。同时,通过增加芯丝数量和Ag/超比例也可增强带材抗拉伸应变能力。The tensile stress-strain characteristics of Ag and AgMn alloy-sheathed Bi-2223 tapes have been studied, and the effects of sheath material, filament number and Ag/core ratio on the critical current of Bi-2223 tapes have been compared. Using the Ag-alloy tube as an outer sheath of Bi-2223 tapes can increase the residual thermal compressive stresses in the filaments, avoid a wavy interface between the Ag sheath and oxide core, and limit the stress concentrations induced by the interface inhomogeneity, thus the micro-crack will be formed at higher stress levels and the tensile strain tolerances of tapes can be improved remarkably. In this study, the critical tensile stress can be improved from 62 MPa to 124 MPa, and the irreversible tensile strain can be improved from 0.31% to 0.52% by using the AgMn-alloy as an outer sheath instead of pure Ag in 37-filamentary tapes. In addition, we found that Bi-2223 tapes can tolerate higher tensile strain level by increasing the filament number and Ag/core ration.

关 键 词：BI-2223带材 不可逆拉伸应变 包套材料 芯丝数目 Ag/超比例 

分 类 号：TM26[一般工业技术—材料科学与工程]