【摘要】 本文主要研究了在77K温度下,拉伸应变和弯曲应变对Bi-2223/Ag超导带材临界电流的影响,得到了超导带材的临界电流随拉伸强度、曲率半径变化规律.实验结果显明,拉伸作用在超导带材上产生的形变对其临界电流(Ic)的影响存在一个临界值εirr=0.3%.形变小于此临界值,Ic变化较小,超过此临界值,临界电流急剧下降.弯曲实验同样存在类似关系.同步辐射光源对超导带材检测表明,在形变情况下,超导氧化物陶瓷芯的微裂纹迅速增加和交织是Ic降低的主要原因.更多还原

【Abstract】 Effects of mechanical properties on the critical current of Bi-2223/Ag tapes have been studied at 77K. There is a critical value. The conductors critical current (I_ c ) keeps nearly constant when the tensile strain is low than the critical value. As tensile strain increase, I_ c decreases slowly at the beginning, and then degrades sharply near 0.3% of strain. Degradations of I_ c caused by the bending strain are in good agreement with the tensile testing results. Synchrotron radiation shows that the degradation of I_ c is related directly with propagation of micro-crack in the oxide layer under tensile tests.更多还原