EFFECT ON THE PHASE-FORMATION OF BI-2223 IN SOME AG-ALLOY SHEATHED PIT TAPES

Powder-in-tube mono- and multifilamentary tapes with sheaths of Ag, Ag Cu0.02, Ag(AgCu0.02), AgAk(0.25), Ag(AgAl0.25), AgNi0.25Mg0.25, AgTi0. 25Mg0.25, and AgTi0.25 alloys have been fabricated and their physico-c hemical properties and effect on the phase formation of Bi-2223 determ ined. Alloying was found to have a significant effect on phase formati on of the Bi-2223 phase formation linked to the alloying elements reac tivity to oxygen Cu < Ni < Al < Mg < Ti. Multifilamentary tapes, compo sed of an inner Ag sheath and an outer Ag alloy sheath showed no such effects. The resistivity and mechanical properties of the various Ag a lloys used as sheathing materials are also reported on and their possi ble use in improving the performance of PIT tapes. (C) 1998 Published by Elsevier Science B.V. All rights reserved.