HEAT TREATMENT METHOD OF OXIDE SUPERCONDUCTIVE WIRE

摘要

PROBLEM TO BE SOLVED: To provide a high critical current by preventing swell or crack of a sheath and large bubbles generated in an oxide superconductive substance caused by gas emission from the inside of the sheath in heat-treating an oxide superconductive wire using Bi-2212 particles and by surely orienting the crystal of the Bi-2212 particles. SOLUTION: Firstly the oxide superconductive wire is exposed in a temperature range higher than a temperature for emitting gaseous oxygen from the inside of the sheath in raising temperature and lower than the melting point of the Bi-2212 particles to sufficiently emit gas, thereafter rapidly heated to a temperature higher than the melting point of the Bi-2212 particles at high speed once, thereafter rapidly cooled to a temperature range lower than the solidifying point of the Bi-2212 oxide super conductive particles and higher than a temperature for growing the crystal of the Bi-2212 particles, and cooled to ordinary temperature after the crystal of the Bi-2212 particles is grown and its orientation is aligned in that temperature range.