Process-Related Problems of YBa sub 2 Cu sub 3 O sub (x) Superconductors

Ceramic processing of YB sub 2 Cu sub 3 O sub (x)-based superconductors and process related problems are described. Conditions for calcination, sintering and microstructural development are important considerations for the superconducting properties. We examine different forming techniques to prepare superconducting components with different sizes, shapes and configurations. We also identity and discuss six problem areas related to (1) incomplete decomposition of BaCO sub 3 precursor; (2) oxidation of YBa sub 2 Cu sub 3 O sub (x) ceramics; (3) sensitivity of the YBa sub 2 Cu sub 3 O sub (x) phase to water; (4) reactivity of the YBa sub 2 Cu sub 3 O sub (x) phase with substrates and co-firing materials, (5) low critical current density in bulk ceramics of YBa sub 2 Cu sub 3 O sub (x) and (6) low mechanical strength of YBa sub 2 Cu sub 3 O sub (x) ceramics.