| 摘要 |
PURPOSE:To make it possible to use liquid nitrogen as a coolant and to maintain a high critical temperature for a long period by filling a material powder of a composite oxide superconductor or a formation of such a powder in a metal pipe, sealing the both ends of the pipe and giving an extrusion process, and then heating it in a zone inductive heating. CONSTITUTION:A material mixture powder is processed in mechanical alloying in an attriter and sintered. And after crushing the resultant sintered substance into powder, it is formed into a columnar form in the hydrostatic pressure formation. The resultant formation is filled in a copper pipe, and extrusion- processed. The extruded material is sintered from one end at a constant speed. This sintering is carried out at a temperature within -10 deg. from the melting point of the powder or the formation filled in the metal pipe setting the melting point as the upper limit temperature, in a zone inductive heating, and the included oxide is deoxidized. The extruded material including the oxide superconductor is formed in such a way. Since a highly stabilized Tc and Tci are obtained in such a way, liquid nitrogen can be used as a coolant to produce the superconductivity. |
