FABRICATION OF AG SHEATHED BI2223 TAPE WITH SUPERCOLD ROLLING PROCESS

A novel mechanical deformation process has been developed to fabricate high quality HTS tapes. In this process, the rolling step in the powd er in tube technique is replaced by a supercold rolling conducted in l iquid nitrogen. The critical current density of the Ag sheathed Bi2223 tapes is significantly enhanced by the supercold rolling. The microst ructure observations of the tapes demonstrate that the supercold rolle d tape has higher mass density and better grain alignment than the roo m temperature rolled tape, which are responsible for the high critical current density.