Patent ID: 8530389

Claim:
A process for the preparation of oxide superconducting rods, said process comprising the steps of: i) preparing a partially preformed tube powder obtained by grinding of a sintered tube made from isotatic pressing of calcined spray dried powder of Ag-added (Bi, Pb) 2 Sr 2 Ca 2 Cu 3 O 10+× superconductor; ii) filling the above partially preformed tube powder obtained in step i) into a rubber mould; iii) cold isopressing the above said partially preformed powder into a rod; iv) initially sintering the rod obtained as such in step (iii) at a temperature in the range of 830-850° C., in air for a period of 50-100 hours; v) roughing both the end portions of the initially sintered rod obtained in step (iv) with a subsequent deposition of a first layer of metal silver and further wrapping it with a perforated silver sheet, followed by further deposition of another layer of metal silver over it; and, vi) finally sintering the whole assembly of initially sintered rod and both end contacts, at a temperature in the range of 800-850° C., for a period of 25-50 hours to obtain the desired oxide superconducting rod.