Phase Development in Ag-Clad Bscco Wires

We have studied phase evolution in Ag‐clad BSCCO wires with nominal composition Bi 2 . 4 . 8 Sr 2.05 Ca 0.95 Cu 2.27 Oy‐ The wires were initially processed at 920°C where the oxide was partiaily moiten, then subsequently annealed at 840° C. The microstructure and composition of the phases present were studied at different points in the processing using optical and scanning electron microscopy, and electron probe microanalysis. The microstructure became simpler during the anneal resulting in two oxide phases and Ag. Ag from the cladding had dissolved into the melt at 920° C and subsequently precipitated in the core of the wire on cooling to the annealing temperature.