STUDY OF POWDER DENSITY, AG-SUPERCONDUCTOR RATIO, AND MICROHARDNESS OF BSCCO-2212 AG-SHEATHED WIRES AND TAPES DURING WIRE DRAWING AND ROLLING

Densification of Bi2Sr2CaCu2Ox (BSCCO-2212) powder cores in Ag-clad wi res and tapes has been studied as a function of strain and initial pac king density. Density was measured directly by etching away the silver and weighing the remainimg core. A-universal feature Tn both wires an d tapes was the attainment of maximum densities (similar to 80%) at in termediate strains of similar to 4. The linear correlation between mic rohardness and density found for round wires breaks down for rolled ta pes, apparently because the core separates into dense blocks separated by cracks.