PROCESSING-MICROSTRUCTURE-PROPERTY RELATIONSHIPS OF AL2O3-FIBER-REINFORCED HIGH-TEMPERATURE SUPERCONDUCTING (BI,PB)(2)SR2CA2CU3OY COMPOSITE

Monolithic high-temperature superconducting (HTS) materials are recogn ized to have inherently weak mechanical properties, such as low streng th and fracture toughness. These drawbacks usually can be improved by introducing strong continuous fibers into the brittle ceramic material s. In this study, a systematic investigation on the relationships amon g processing variables, microstructure, and superconducting and mechan ical properties of a continuous Al2O3-fiber-reinforced HTS (Bi,Pb)(2)S r2Ca2Cu3Oy composite is presented. The Al2O3/BPSCCO composite is fabri cated initially by a slurry method, followed by binder extraction up t o 800 degrees C in an 8% O-2 atmosphere, and finally hot pressed at 80 0 degrees C in air. Phases present in the HTS composite are identified by XRD, and the microstructure and microchemistry studied by SEM and EPMA. Of particular interest is the fiber/matrix interface; the interf acial reaction is studied for composite specimens which have undergone long heat treatment. The I-ITS composite is observed to have a good c ombination of superconducting properties and mechanical properties.