Ceramic superconductor parts made with higher current density - by using magnetic field to orient crystallites during filling of forms before compression at elevated temp.

摘要

The high temperature superconductive parts based on ceramic are made by compression of a powder. Before and possibly during the compression stage the crystallites are oriented by a magnetic field to align the axes of highest critical current density in parallel. The powder particles are pref. vibrated, pref. by ultrasonic agitation. Pref. two concentric hollow tubes (1,2) are used between which the powder is compacted by expansion of the inner tube radius. The inner tube pref. consists of a ductile material, pref. Ag, which is expanded by gas pressure, pref. O2. The outer tube is pref. Ti or steel. The thick film mfg. method uses 2 parallel plates between which the powder is compacted. The compression pref. is carried out under O2 pressure while at least one of the plates is permeable to this. Afterwards the material is sintered, pref. under pressure, while the magnetic field is pref. maintained. USE/ADVANTAGE - The magnetic field improves the orientation of crysallite axes and as a result allows the crystallite orientation to be adjusted for max. critical current density.