High temperature characterisation and structural analysis of PRD-166 alumina zirconia fibres

Results are presented from a mechanical characterization study, at room temperature and at elevated temperatures up to 1300 C, and structural analyses of PRD-166 alumina zirconia fibers (continuous fibers composed of 80 percent alpha alumina and 20 percent zirconia). The alpha alumina and zirconia in the PRD-166 fiber give the structure a distinct grain population. The largest grains, of about 1 micron are of alpha alumina, while zirconia occurs in the form of grains of 0.1 to 0.5 micron. These relatively large crystals are surrounded by microcrystals (about 10 nm in size) of the same materials. The large alumina grains act as defects which limit the strength of the fiber at temperatures at which the tensile behavior is linearly elastic. At higher temperatures, the tensile behavior of the fiber becomes nonlinear, and the microstructural mechanisms are more complex. 8 refs