PLASTICITY OF CUBIC ZIRCONIA BETWEEN 700-DEGREES-C AND 1150-DEGREES-C OBSERVED BY MACROSCOPIC COMPRESSION AND BY IN-SITU TENSILE STRAINING TESTS

Plastic deformation and dislocations microstructure of the of Y2O3-stabilized cubic ZrO2 has been studied by means of macroscopic deformation tests in air at temperatures between 700 degrees C and 1150 degrees C and subsequent transmission electron microscopy as well as in situ straining experiments in a high voltage transmission electron microscope at 1150 degrees C. Compression in the [1 $($) over bar$$ 12] direction invokes the (001)[1 $($) over bar$$ 10] slip system, that already has been confirmed at higher temperatures. At lower temperatures the dislocation microstructure is determined by screw dislocations of zig-zag shape in narrow slip bands. The in situ experiments at 1150 degrees C demonstrated the instantaneous creation of a complex dislocation microstructure consisting of slip bands of parallel edge dislocations accompanied by areas with dislocation loops and dislocations with screw components.