The Effects of Drawing Parameters on Sausaging and Critical Current Density of Bi-2223 /Ag HTS Wires

Bi-2223/Ag superconducting wires have been mainly prepared by the powder-in-tube method. Drawing and rolling are the main processes used to increase the core density and wire length. In the fabrication of long wire, especially, the drawing should be precisely controlled to assure the filament homogeneity. In this paper, the influences of drawing die angle, bearing length and reduction ratio on the sausaging and the critical current density of the wire are investigated. Single-cored and multi-filamentary wires are fabricated by the PIT method with different conditions. The core density and the sausaging in the wires are investigated and are discussed regarding their relationships to the I_c. It was made clear that sausaging is sensitive to the geometry of drawing die. Improvement in I_cand a high core density were achieved by reducing the die angle.