MAGNETIC MELT TEXTURING COMBINED WITH HOT-PRESSING APPLIED TO SUPERCONDUCTING (2223)BI-PB-SR-CA-CU-O CERAMICS

We describe a new texturing process for superconducting ceramics which combines the effects of magnetic melt texturing (MMT) and hot pressin g (HP), referred to in the following as the MMHPT process. This proces s essentially involves three steps: (i) a hot pressing at a temperatur e T-P, (ii) a partial melting in a magnetic field at a slightly higher temperature T-M, (iii) a second hot pressing at the same temperature T-p. Optimization of the thermomechanical treatment in a magnetic fiel d applied to the (2223) Bi-Pb-Sr-Ca-Cu-O cuprates led to highly textur ed and dense samples carrying transport current density J(c) of 3800 A cm(-2) at 77 K in zero field.