Thermomechanical processing of Ag-clad Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub x} superconductors

Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub x} (2212) powders were synthesized by solid-state reaction, loaded into Ag tubes, and processed into tapes by various combinations of drawing, rolling, and heat treatment. Critical current densities at 4.2 K of greater than 10{sup 5} A/cm{sup 2} were achieved from microstructures consisting of large, highly textured 2212 grains. Optimal microstructures were produced by specific mechanical-working conditions and heat-treatment schedules that incorporated solid-state and partial-melt sintering. The relationships between processing, microstructure, and critical current density will be discussed.