PURPOSE: To obtain a superconductor preferable in characteristics by charging precursor powder, which is formed by temporarily baking material powder in the atmosphere at low oxygen partial pressure so as to pulverize it, into a metallic sheath, and hot working it above the Tammann temperature of the powder but below the melting point so as to form the shape, and then applying heat treatment in proper atmosphere.
CONSTITUTION: When forming superconductive compact in oxide line consisting of rare earth or Bi and alkaline earth metal, Cu, and O, the material powder is temporarily baked under low O2 partial pressure and then pulverized, and deformation resistance to the processing stress is decreased apparently, and secondary material powder is charged into a metallic sheath and hot-worked above Tammann temperature (melting point Tm×0.6) and below Tm. If Tm or its vicinity is used, processing speed is fast. And if the temporary baking is done below 1 atmospheric pressure for total pressure and below 10torr for partial pressure, auxiliary phase is hardly created. The compact obtained by hot-working is heat-treated in O2 as occasion demands to make it contain necessary oxygen amounts. In this case, the sheath material is limited only to that which is easy for O to diffuse such as Ag, etc.
ENOMOTO KENJI
TANAKA YASUZO
OKANIWA KIYOSHI
TAKAHASHI HIROO
OGAWA KIYOSHI
KURIHARA TAKESHI
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