| 摘要 |
PURPOSE:To obtain a stable fusion band to increase the critical current density of the wire rod, by preheating a sintered wire rod of oxide superconducting composition to above 700 deg.C, and partially heating only a part within its heated region to temperatures above its fusion point so as to form the fusion band. CONSTITUTION:After a compact of powder with composition Bi2-Sr2-Ca-Cu2-O has been packed and sealed in an Ag pipe, the pipe is then swagged to reduce its diameter to about 3mm so that it is formed into a wire rod, and thereafter an Ag sheath on its surface is dissolved by methanol nitrade. An oxide wire rod is next subjected to heat treatments in oxidizing atmosphere for ten hours to obtain a raw wire rod 1. The wire rod 1 is next fixed at both ends by wire rod holders 6a, 6b and an oxidizing gas is supplied around a coil 4b and then electricity is transmitted to a heating body 4a to heat the wire rod 1 to above 700 deg.C, and electricity is transmitted to the coil 4b to partially heat the wire rod 1 so that a suspended fusion band 3 is formed where the wire rod is melted. A supply driving shaft 8 is driven and raised to take the wire rod 1 out of a furnace to obtain an oxide superconducting wire rod 2. Wire rod 2 from which gaps are removed can thus be obtained continuously. |
