The effect of intermediate deformation processing on J(c) of Ag/Bi-2223 tapes

Normal rolling, "sandwich" rolling, pressing, hot-pressing, and cryogenic p ressing were used as the intermediate mechanical deformation for making Ag- clad Bi-based superconducting tapes. Magneto-optical imaging results were t aken to study the density of the microcracks and the distribution of the mi crocracks. J(c) of sandwich rolled tape is 35% higher than the normal rolle d tape. J(c) and relative density of the tapes with three different process es (normal rolling, "sandwich" rolling, and pressing) are increased when in creasing the reduction rate, then reached a peak at optimal reduction rate and decreased at large reduction rate.