Effect of cryogenic deformation on microstructures and critical current density in Ag/Bi-2223 tapes

The microstructure and J(sub c) of Ag/Bi-2223 tapes was studied under cryogenic processing conditions to determine the effect of deformation rate and silver hardness. Improved grain connectivity, alignment, Ag/core interface and critical current density resulted from cryogenic deformation. A significant increase in the hardness of silver sheath resulted during cryogenic mechanical deformation at room temperature. A 20% reduction rate of the maximum J(sub c) appeared for the tape thickness for cryogenically processed Ag/Bi-2223.