The effect of intermediate deformation processing on Jc of Ag/Bi-2223 tapes

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