Performance and Microstructure of Bi-2212 Wire under Different OverPressures Heat-treatment

Abstract

Bi2Sr2CaCu2Ox is a potential material for the superconducting magnets of the next generation of Fusion-reactors. A R & D activity based on Bi-2212 wire is running at Institute of Plasma Physics Chinese Academy of Sciences (ASIPP) for the feasibility demonstration of Cable In Conduit Conductor (CICC). The Bi-2212 round wires were heat-treated by the tube furnace at a pressure of 30 atm and 50 atm. Wire diameter, critical current performance, and n value were studied. The surface morphology and grain size distribution of Bi-2212 superconductor after heat treatment analyzed by Electron Backscattering Diffraction (EBSD). The performance difference of Bi-2212 at 30atm and 50atm is small, and the grain size and distribution are similar. The performance difference of Bi-2212 samples with 30atm and 50atm over-pressure heat-treatment is small. 30atm requires less equipment and can obtain a longer constant temperature zone, which is suitable for exploring the heat treatment process of a long conductor.