Characteristics of HTS tube depending on heat-treatment conditions

摘要

Bi-2212 HTS tube was fabricated by centrifugal forming process (CFP). As a variation of melt casting process (MCP) or centrifugal casting technique, the CFP is a flexible method for manufacturing Bi-2212 bulk tubes and has been optimized to achieve smooth surface and uniform thickness. At this process, the slurry was prepared in the mixing ratio of 10:1 of Bi-2212 powder and binder. It was initially charged into the rotating mold at the speed of 300-450 rpm. Heat -treatment was performed at the temperature rang 870-890 deg C in air for partial melting. The HTS tube fabricated by CFP at 890 deg C at the rotating speed of 450 rpm was highly densified and the plate-like grains with more than 20 #MU# m in diameter were well developed along the rotating axis. The measured T_c and J_c at 10 K were around 85 K and 3000 A/cm~2, respectively.