Processing technique for fabrication of advanced YBCO bulk materials for industrial applications

We present a processing technique for fabrication of advanced semi-finished parts and products based on the high-temperature superconductor (HTSC) YBa/sub 2/Cu/sub 3/O/sub 7-x/ (YBCO). High-quality YBCO bulk components are produced powder metallurgically by sintering and partial melting of precursor powders. Depending on size, shape, tolerances and levitation requirements, parts are either die-pressed or precision machined from isostatically pressed blocks. The oxygenation process can be monitored in-situ by a macro-thermogravimetric analyzer. The texture of the bulk of full-size pellets was verified by elastic neutron scattering. Levitation properties under static and dynamic load levels were analyzed using a test bench with a three dimensional force sensor unit. Flux mapping was used to verify the homogeneity of the material, to evaluate macroscopic critical currents and to investigate the field trapping capability. Several HTSC frictionless bearing modules have been built. They are manufactured in various sizes, ranging from O 40 mm to O 140 mm. Lifting forces are up to 200 N per bearing module. Applications for the bearings are seen for mechanical components in high speed rotating machinery, in cryogenic systems, gyroscopes, transportation systems and vibration isolation.