The microstructure characterization and phase composition analysis of (Bi,Pb)- 2223 Ag/tapes with SnO, MgO and Ag2O mix-doping

In this paper, the two kinds of precursor powders of BiPb2212 and CaCuO2 were prepared by double powder method and an improved coprecipitation method, then the BiPb2212 powders were fabricated by mechanical grinding and hand grinding. The BiPb2212 powders and CaCuO2 powders were prepared by two kinds of grinding methods mixed with a certain proportion of grinding, the multi-core Bi2223 superconducting tape with 37 cores were prepared by removeing the carbon、filling tube and annealing. The XRD analysis、SEM observation、laser particle size analysis and the tap density test of the precursor powders of the BiPb2212 were carried out respectively by mechanical grinding and hand-grinding.The results showed that the phase composition, microstructure, particle size distribution and tube density detection were all significant differences by the using two kinds of grinding methods. Finally, the superconductivity test of the heat treatment strip of Bi2223, the results show that the Bi2223 multi-core strip at 77K, the critical current from the field improved from 86A(hand-grinding method) to 127A( mechanical grinding method). Therefore, the the precursor powder by using mechanical grinding method, the Bi2223 multi-core strip is more conducive to obtain high-performance.