Isothermal melt processing of Bi-2212 wires and tapes

摘要

Isothermal melt processing has been used to produce high critical currents (I(sub c)'s) and current densities (J(sub c)'s) in Bi2Sr2CaCu2O(sub y) round wires and flat tapes. I(sub c)'s and J(sub c)'s of 225 A and 80 kA/sq cm have been obtained in short length, monocore wires. However, voids and other macroscopic defects have limited performance over longer lengths. Isothermally melt processed tapes have yielded I(sub c) and J(sub c) values up to 341 A and 245 kA/sq cm, although performance over longer lengths is somewhat reduced. A test coil made from 0.5 m of tape yielded, I(sub c) and J(sub c) values of 208 A and 153 kA/sq cm, respectively.