ABSTRACT
The fabricating of HTSCs, which are brittle oxide ceramics, into reliable and robust commercial products is an extremely challenging and formidable task. Over the past few years, several processing techniques, such as powder-in-tube (PIT), sinter forging, hot isostatic pressing, tape casting, and use of a doctor-blade, have been developed [8,10,1214]. At 77 K, the transport properties of the conventionally consolidated and sintered Bi2223 samples are very low [15]. Although very good superconducting properties have been achieved in Bi-2212 tapes fabricated by tape casting, this technique is not commercially feasible because one side of the tape is exposed to the environment [14]. On the other hand, BSCCO conductors made by the PIT process seems to exhibit very good transport properties [7-9, 16-26]. The groups at Vacuumschmeize and Sumitomo Electric Company were the first to apply PIT processing to HTSC materials such as the BSCCO system [13,27]. Texturing and grain alignment, which dictate the superconducting properties of the BSCCO tapes, can be very easily achieved with a series of thermomechanical treatments [21,28,29]. The main advantage of the PIT process is its similarity to a technique used in fabricating long lengths of low-7c (critical temperature) superconductors such as NbTi and Nb3Sn. Because the technical know-how for fabricating low-Tc superconductors has long been established, the operating and setup cost for high-7, superconductors would be substantially lower [30].
