Superconducting Properties of Artificial Pinning CentreNb48Ti/Cu Composites with Ti5Nb Pins

摘要

High performance superconducting NbTi/Cu is usuallyfabricated by metallurgical treatment process because large quantity ofalpha Titanium particles, which act as effective flux pinning centres, areformed during thermal mechanical process. In this paper, the similar pinswith the elemental composition of Ti-5 atomic% Nb were artificiallyintroduced into NbTi/Cu multi-filamentary composites by rod-basedprocess. The composite with 20 wt.% of Ti5Nb artificial pinning centers(APC) shows higher critical current density and flux pinning force at lowmagnetic fields and lower properties at high magnetic fields, as comparedwith the composites having 10wt% Ti5Nb APC. Meanwhile, upper criticalmagnetic field is decreased when more quantity of Ti5Nb APC areintroduced into NbTi/Cu superconductor. In addition, the critical currentdensity decreased obviously when heat treatment process was utilized formore precipitates which would act as flux pinning center. The more heattreatment is used, the lower performance is, even though the temperature isvery low.