| 摘要 |
PURPOSE:To stabilize the high quality of the superconductor at a low cost by calcining the mixed powder of a Bi oxide, etc., in a specified vessel at a temp. lower than the sintering temp. in an oxidizing atmosphere, press-forming the obtained crushed and granulated powder, and sintering the formed product in a sintering vessel. CONSTITUTION:The Bi-Pb paste obtained by kneading the mixed powder of Bi2O3 and PbO with water is applied on the inner walls to obtain the calcination vessel 1A and sintering vessel 1B provided with coated layers 2. The powder of Bi2O3 having <=10mum particle diameter, the powder of PbO, the powder of SrCO3, the powder of CaCO3, and the powder of CuO are then mixed to obtain mixed powder 3. The powder 3 is charged into a vessel 4, and placed the vessel 4 in the vessel 1A through a spacer 5. A lid 6 is set, and then the powder is calcined at about 830 deg.C in an oxidizing atmosphere in a calcination furnace. The calcined material is crushed, granulated, and press-formed to obtain a formed product 7. The product 7 is arranged in the vessel 1B contg. the bottom powder 8 having the same composition as the product 7 through a spacer 5, and the lid 6 is fixed. The vessel 1B is then sintered at 830-880 deg.C in an oxidizing atmosphere in the sintering furnace to produce the superconductor. |
