论文信息 - Influence of Filament Number on Workability and Critical Current Density of Bi-2212/Ag Superconducting Wires

Influence of Filament Number on Workability and Critical Current Density of Bi-2212/Ag Superconducting Wires

The important merit of Bi-2212/Ag high Tc superconducting wire is to apply cable as round wire geometry. Bi-2212/Ag wires were fabricated in order to develop Rutherford cable for SMES near the future. Various Ag ratio and various numbers of filaments for PIT (powder-in-tube) process were applied to investigate the workability during drawing and to improve critical current property of the wires. In order to find proper working process, we investigated the variation of drawing stress during working. Post-annealing of Bi-2212/Ag wires at various atmospheres was carried out after main heat-treatment in order to increase critical current density. The results of post-annealing in nitrogen were better than that of post-annealing in oxygen. Jc of Bi-2212/Ag wire was increased as increased maximum temperature,Tm , for partial melting until 890degC, and highest Jc was over than 2000 A/mm2. The shape of grain was observed by SEM to investigate Bi-2212 phase formation in filaments. The critical current density increased in proportion to the increase of Bi-2212/Ag wire's filaments number.

[1] T. Hasegawa,et al. Improvement of superconducting properties of Bi-2212 round wire and primary test results of large capacity Rutherford cable , 2001 .

[2] T. Graf,et al. Superconducting and magnetic properties as a function of the oxygen content in the Bi2Sr2CaCu2O8+δ phase , 1991 .

[3] M. Meinesz,et al. Development of round multifilament Bi-2212/Ag wires for high field magnet applications , 2005, IEEE Transactions on Applied Superconductivity.

[4] Kenji Tasaki,et al. Test Results of an Experimental Coil with Bi-2212 Rutherford Cable for High Energy-density HTS-SMES , 2006 .

[5] Ulf P. Trociewitz,et al. The generation of 25.05 T using a 5.11 T Bi2Sr2CaCu2Ox superconducting insert magnet , 2004 .

[6] L. Gauckler,et al. Critical current density of Bi-2212 thick films processed by partial melting , 1997 .

[7] T. Hasegawa,et al. Bi2Sr2CaCu2Ox/Ag multilayer tapes with Jc>500 000 A/cm2 at 4.2 K and 10 T by using pre-annealing and intermediate rolling process , 1998 .

[8] H. Kitaguchi,et al. Performance tuning and improvement of Jc?B characteristics for Bi-2212/Ag tapes by controlling the excess oxygen content , 2004 .