Bi-2223/Ag 고온초전도 선재의 bubbling 제어에 관한 연구

A Study on Bubbling Control of Bi-2223/Ag HTS tapes

Bi-2223/Ag HTS tapes fabricated by PIT process are used to make the power transmission cable, motor, fault current limiter, transformer etc. But some problems are still remained as like bubbling, sausaging to got the high Jc. In this study. we carried out the experiment to prevent bubbling in the HTS tape. The bubbling mainly occurred when HTS tape was heat-treating. Therefore, additional vacuum annealing at 400 ~ $600^{\circ}C$and slowly ramp-up sintering method were used to decrease the bubbling. slowly ramp-up sintering was more effective to decrease the bubbling than the vacuum annealing, but Jc was also decreased after heat treatment. Optimum ramp-up sintering schedule was searched to get the high critical current and prevent bubbling at same time.