INVESTIGATIONS ON THE TEXTURE OF BI-BASED SUPERCONDUCTOR TAPES

The effects of successive thermomechanical treatments on the texture a nd morphology of Bi-based (2223) superconductor Ag-sheathed tapes were analyzed and related to the critical current density. Pressing and ro lling mechanical processes were compared. X-ray diffraction results sh owed a large increase in the crystalline density and preferred orienta tion in the initial steps, and saturation after the third cycle of mec hanical effort-heating. Scanning electron microscopy photographs showe d differences in the morphological aspects of pressed and rolled tapes ; the grains of the pressed tapes presented piled-up platelets paralle l to the tape surface, a factor that was associated with the current d ensity.