Powder-in-tube-processed multifilamentary Bi-(2223) tapes with silver-alloy sheaths

Superconducting Bi-(2223) multifilamentary tapes with Ag/sub 100-x/Y/sub x/ alloy sheaths, with Y=Cu, Mn and Pd, were made by the oxide-powder-in-tube technique. All resistivities of the Ag alloy sheaths exceed that of the pure Ag sheath by at least a factor of 2. The maximum resistivity was achieved for Ag/sub 99/Pd/sub 1/ with /spl rho//sub 77K/=1.3 /spl mu//spl Omega/cm. Tapes sheathed by Ag/sub 90/Cu/sub 10/ exceed the critical current density, J/sub C/, of pure Ag sheathed ones. J/sub C/ up to 26 kA/cm/sup 2/ were achieved by pressing Ag/sub 90/Cu/sub 10/ sheathed tapes during the thermo-mechanical-treatment, TMT. For thinner Ag/sub 90/Cu/sub 10/ sheathed tapes up to 31 kA/cm/sup 2/ were obtained employing flat rolling during TMT. Measured irreversibility lines of thin and thicker tapes with comparable J/sub C/ suggest, that thicker tapes have a larger pinning strength and a better grain texture but thinner ones a better grain-to-grain connectivity.