中文摘要：

对4种Bi系2223高温超导带材77K下的力学性质进行了实验研究。通过选择合适的合金包套替代传统的银包套，带材的机械性能能有所提高，但电学性质有所降低，尤其是内包套采用合金、外包套采用银，其机械性能反而低于纯银包套带材。通过X射线衍射图谱发现，当包套采用合金材料，尤其是内包套采用合金、外包套仍采用纯银，会大大降低样品中2223相的体积含量。相比较临界电流密度，n值对材料的破坏更为敏感。利用X光同步辐射技术初步探讨了银包套带材在室温和77K下的损伤破坏过程。

英文摘要：

The mechanical properties of four types of Bi-based 2223 high temperature superconducting （HTS） tapes were studied at 77 K. The result shows that the mechanical property of tapes could be partly improved by using suitable alloy-sheaths instead of Ag-sheath tape, but the electrical property will decrease in reverse, especially for the tape with alloy inner-sheath and Ag outer-sheath. By the XRD pattern, it demonstrates that the content of 2223 phase will decrease when using alloy-sheath instead of Ag-sheath, especially using alloy for inner-sheath and Ag for outer-sheath. The experimental results also demonstrate that nvalue is more sensitive to the damage of tapes than the critical current density. Finally, the synchrotron radiation technique is taken to study the damaging process of Bi-system 2223/Ag tapes under tensile stress at room temperature and 77 K.