PRESINTERING PROCESSING OF BI-BASED BULK SUPERCONDUCTOR BY SLURRY PRESSING

A Bi-based superconductor, usually known as BPSCCO (Bi,Pb)2Sr2Ca2Cu3O1 0+delta (2223 phase, T(c) 110 K), derived through decomposition of an acrylate precursor has been prepared by a slurry pressing route. The p owder was dispersed in various liquids such as water, isopropanol, and acetone, and the respective slurries compacted uniaxially in a die de signed for the purpose using different modes of application of pressur e. Compaction densities as high as 56% of theoretical were obtained. P ressed compacts were dried and sintered at 845-degrees-C to higher den sities. The best packing and particle alignment were obtained from a 6 0 wt-% powder suspension in isopropanol under a compaction rate of 5 m m min-1 and a maximum pressure of 10 MPa. The microstructure developme nt in the green and sintered compacts were investigated and compared w ith a uniaxially consolidated and sintered BPSCCO sample having random orientation. (C) 1993 The Institute of Materials.