OPTIMIZATION OF THE BI(PB)-2223 BULK TECHNOLOGY

Bulk Bi(Pb)-2223 ceramics affords a possibility for various applicatio ns like current leads, fault current limiters, magnetic shields and ma gnets. Evidently their practical use depends on the properties gained by the applied processing i.e. on a number of the technological parame ters. In spite of their complex character several steps were distingui shed and investigated. The optimum starting composition was found to b e x similar to 0.3, and the optimum sintering temperature for x = 0.26 at similar to 835 degrees C (Bi2.1-xPbxSr2Ca2Cu3O10+delta), The inter mediate cold pressing enhances significantly the exaggerated growth of highly oriented Bi-2223 grains. With respect to the required grains o rientation either uniaxial or isostatic pressing should be applied. Th e investigation of the texture ''gradient'' across the walls of the su perconducting tubes resulted to, their optimized thickness of similar to 2 mm. On the basis of the study the superconducting magnet with the trapped magnetic flux density of 0.5 T at 20 K inside the magnet hole was constructed.