The effect of cryogenic rolling on critical current density of Bi-2223/Ag HTS tapes

Bi-2223/Ag 고온초전도선재의 Jc와 미세조직에 미는 저온압연의 영향

In order to investigate the effect of cryogenic rolling on the critical current density (Jc), 54 and 55-multi-filament Bi-2223/hg tapes have been fabricated using a PIT process including two different types of cooling methods. The densification of oxide filament was found to occur due to the cryogenic rolling, and this enhanced the critical current density. However, when the wire was fully immersed in liquid nitrogen used as the coolant in cryogenic rolling, Jc degradation appeared caused by the nitrogen penetration into the filament. The cryogenically rolled tape with an improved type of cooling showed approximately 10％ Jc's increase.