【摘要】 利用Nb片和Ti片交替组配加工 ,经扩散反应制备了Ti含量从 4 3WT %到 5 7WT %之间的三种不同成份的NbTi超导线 .测量了三种不同成份的临界电流密度Jc,讨论了在磁场下不同Ti含量对NbTi线临界电流密度Jc 的影响 ,并对磁通钉扎机制进行了分析 .通过扫描电镜 (SEM)观察了Nb/Ti界面扩散形态及微结构 ,并运用多源标度分析法[1 ] 对不同成份的NbTi超导线进行了磁通钉扎力密度随磁场变化曲线的拟合 .结果表明 :随着含Ti量的增加 ,其临界电流密度在低场时很高 ,而在高场时的性能偏低 ,且下降迅速 ,而含Ti量低的超导线在高场时的性能更具有优势 ;超导线在不同磁场下的性能是由点钉扎和面钉扎两种钉扎机制共同作用决定的 .更多还原

【Abstract】 Three different compositions of NbTi wires have been fabricated by using alternately niobium sheets and titanium sheets. The Ti content may vary from 43WT% to 57WT% by adjusting the relative thickness of the Nb and Ti sheets in the monofilaments. The effects of different Ti content on NbTi superconductor′s critical current densities and flux pinning mechanism were discussed. The Nb/Ti interface microstructure and cross-sectional morphology diffusion have been investigated by scanning electron microscopy (SEM). The curve of F_p∝B at different composition have been fitted. The results show that the critical current density ( J_c ) can be improved with higher Ti content in the low field rang(<5T),but the property was weak and rapidly fall in the high field. There are two kinds of flux pinning mechanism dot pinning and subface pinning affect the property in different field.更多还原