| 摘要 |
PURPOSE:To contrive improvement in superconducting characteristics, such as superconductivity critical temperature, of a superconducting substance, by specifying pressurizing condition during press forming in blending given raw material powders, calcining, pulverizing, press forming and sintering the resultant blend to produce the superconducting substance. CONSTITUTION:Raw material powders, such as yttrium oxide, copper oxide or barium carbonate, for producing a superconducting substance are blended in a given proportion and the resultant blended powder is calcined to pulverize the calcined substance. The pulverized substance is subsequently press formed. In the process, pressurizing is initially carried out at about 10% of the target pressurizing value in a short time and the pressure is then once returned to ordinary pressure. Pressurizing is subsequently carried out to the target pressurizing value. Sintering is then conducted at the target pressurizing value to afford the aimed superconducting substance. Furthermore, the pressurizing condition is condition indicated in the figure and both (theta1) and (theta2) are <=500kg/cm<2> per min, preferably 200-300kg/cm<2> per min. Pressurizing times h1 and h2 are as follows. >=5sec, preferably 10-20sec (h1) and preferably about 30sec-5min (h2). |
