弯曲应变对Bi2223/Ag带材临界电流的影响  

Effects of Bending Strain on Critical Current of Bi2223/Ag Tapes

作　　者：李利[1] 谢述锋[1] 王德义[1] 

机构地区：[1]中国船舶重工集团公司第七二五所,河南洛阳471023

出　　处：《材料开发与应用》2012年第2期47-50,共4页Development and Application of Materials

摘　　要：本文主要研究了Bi223/Ag带材的弯曲应力-应变特征及弯曲疲劳对其在77K自场下临界电流的影响。分析临界电流Ic降低的原因是应变和热循环引起的超导陶瓷芯内部的微裂纹。实验研究发现当带材的弯曲应变超过0.3%以后,Ic显著降低;当带材受到多次弯曲时,前四次弯曲会使Ic急剧降低,然后Ic降低非常缓慢。因此,在实际应用过程中,应使Bi223/Ag带材的弯曲应变不超过0.3%,且在Bi223/Ag带材的生产和使用过程中,均应尽量减少其弯曲的次数。Bending stress-strain characteristics and effect of bending fatigue on critical current of Bi2223/Ag tapes are investigated at 77K under self field.The results shown that critical current Ic reduction is due to the micro cracks of superconductive ceramic core caused by the bending strain and thermal cycle.Experimental study found that Ic declined obviously when the bending strains of tapes was more than 0.3% and significant decrease of Ic occurred within 4 cycles and then the decrease became gentle in repeated bending test.Therefore the bending strain of Bi2223/Ag tapes should not exceed 0.3% in application,and Bi2223/Ag tapes should be bended as few times as possible in process of production and use.

关 键 词：临界电流 弯曲应变 弯曲疲劳 Bi223/Ag带 

分 类 号：TG132.26[一般工业技术—材料科学与工程]