The effect of fabrication pressure on critical transport current density in press-sinter processing of Bi(2223)Ag tapes

Critical current at 77 K and microhardness measurements were used to study the effect of pressure in uniaxial cold pressing and a press-sinter schedule in Ag-clad Bi(2223) tapes. Three types of tape containing different 2223/2212 phase ratios were prepared by the same powder in tube process and subsequently pressed and sintered in several cycles with rising, constant, and declining pressure. The sintering was performed at constant temperature and time interval in air. The effect of uniaxial cold pressing on critical current density at 77 K is discussed with the aim of finding out its optimal value in every press-sinter state.