Influences of Preparation Conditions on Melting and Reformation Behaviors of (Bi,Pb)-2223 Core in the Ag-Sheathed Tape

Abstract

Three kinds of Ag-sheathed (Bi,Pb)2Sr2Ca2Cu3O10 ((Bi,Pb)-2223) monofilamentary tapes were fabricated by powder-in-tube (PIT) process under different conditions. The phase evolutions during melting and reformation of (Bi,Pb)-2223 core in them have been investigated by ex-situ X-ray diffraction (XRD) analysis. The short tapes were melted at 855°C, 858°C in 7.5% O2 balanced with argon, and then slowly cooled to 801°C and 804°C at 1.5°C/h, respectively. The results show that the (Bi,Pb)-2223 phase can reform directly from the melt in all three tapes if the appropriate melting temperatures are used. However, the ceramic cores underneath the silver sheath exhibit different melting and recrystalization behaviors, as the differences of phase compositions in the original tapes before melted.