Ceramic high temp. superconductor prodn. - by pouring starting material into mould, heating, cooling, thermally treating in oxygen@ and cooling, for shield magnetic fields in switching elements

摘要

Prodn. of a ceramic high temp. superconductor (HTSC) in the form of a large moulding made of a powdered starting material comprises: (a) pouring the material into a mould; (b) mould is heated to a 1st temp. to melt the material under low O2 partial pressure and sealed to a melt; (c) mould is cooled to a 2nd temp., in which the melt is solidified to moulding; (d) moulding (3) is thermally post treated in O2 to give a superconductor of high current density; (e) moulding (3) is cooled to room temp.; and (f) moulding (3) is removed from mould (2). Mould (2) is pref. annular and moulding (3) is a hollow cylinder having an inner dia. (d1) of more than 10 cm, height (h) of more than 1 cm and a wall thickness of less than 5 mm. Superconductor is pref. of formula Bi2 Sr2 Ca1 Cu2 O8+x or Ti2 Ba2Ca2Cu3O10+x. USE/ADVANTAGE - HTSC can be used to shield magnetic fields in switching elements.