Rolling characteristics of multi-filamentary Bi-2223/AgAu tapes and roller diameter′s effect on transport properties

Abstract

37-filamentary Bi-2223/ AgAu tapes were fabricated by powder in tube technique. The round wire (φ1.51 mm) were rolled to 0.30 mm tapes by 150 mm, 250 mm and 300 mm roller through flat rolling, respectively. A fundamental understanding of filaments deformation and roll diameter′s effect on critical current properties were systematically investigated. By analyzing the stress distribution on cross section during rolling, it can be understood that the deformation of the filaments at different positions during the rolling of multi-filamentary Bi-2223/AgAu tape is inhomogeneous. According to the deformation extent of filaments, the cross section of the tape can be divided into three areas, namely easy deformation zone, difficult deformation zone and free deformation zone. The average filament width in the free deformation zone is only 65.1 % of the filament width in the easy deformation zone. It can be noticed that the Jc values increase monotonously with increasing roller diameter. Due to more sufficiently deformed filament and flat interfaces, Jc reached the maximum value of 15.7 kA/cm2 on the 300 mm roller sample.