PRODUCTION OF HIGH-TEMPERATURE SUPERCONDUCTIVE CERAMIC MATERIAL BY MECHANICAL ORIENTATIONAL METHOD

摘要

PURPOSE:To enhance orientational property of grain, packing fraction and critical current density by packing the specified grains into a vessel and thereafter vibrating this vessel on an acoustic vibrator and performing orientational control of grain and press-molding the grains at right angle for the orientational direction and thereafter calcining the molded body. CONSTITUTION:The raw material powder of high-temp. superconductive ceramic whose grain has shape anisotropy is mixed and molded. This molded body is roasted at 600-900 deg.C and thereafter calcined at 1000 deg.C or more for a long time in the oxygen atmosphere to obtain superconductive oxide ceramic (A) of large grain. Then the A component is ground into a plane shape or a needle shape by utilizing shape anisotropy and sorted to obtain grains 1. Then the grains 1 are introduced into a vessel 2 and placed on an acoustic vibrator 5 and vertically vibrated. Thereby orientational control is performed for the grains 1. Then the grains 1 are pressurized vertically and uniaxially and calcined at 900-1000 deg.C for about 5 hours. Thereafter the grains are slowly cooled until room temp. at about 0.3 deg.C per minute and high-temp. superconductive ceramic material shown in a formula (0