Deformation-induced texture in cold-rolled Ag sheathed bi(2223) tapes

✍ Scribed by G. Grasso; A. Perin; R. Flükiger

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 510 KB
• Volume: 250
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(95)00348-7

✦ Synopsis

We have found that the Bi(2212) grains in unreacted Ag/Bi(2223) tapes at the end of the cold-rolling process show already a high degree of texture. X-ray diffraction analysis and current transport measurements at 77 K in magnetic fields up to 0.5 T have been performed before and after reaction on tapes with thicknesses in the range from 75 to 286 I~m (filament thicknesses between 30 and 115 Ixm). The critical current density j~ increases for smaller tape thicknesses, a maximum being found for a tape thickness of about 90 p,m, below which sausaging effects are observed. The mean misalignment angles of Bi(2223) grains in these tapes have been determined by angle-dependent transport critical current data at 77 K. We have found that the main reason for the enhancement of j¢ for thin tapes is due to the higher average texture of the Bi(2223) grains when compared to thick tapes. This is a direct consequence of the high degree of texture of Bi(2212) grains after the cold-rolling process, which has been observed here on 90 Ixm thick tapes with j~(77 K, 0 T) reaching between 25 and 30 kA/cm 2.