PLASTIC-DEFORMATION OF CUBIC ZIRCONIA AT TEMPERATURES BETWEEN 1150-DEGREES-C AND 700-DEGREES-C

The plastic deformation of cubic ZrO2 single crystals containing 11 mol.% Y2O3, which were considered to be brittle below about 1100 degrees C, was studied in compression along [($) over bar 11 ($) over bar 2] between 700 and 1150 degrees C. Single slip was observed on a (001)[1 ($) over bar 10] slip system, which is the primary slip system at higher temperatures. Screw dislocations of zig-zag shape in narrow slip bands dominate the microstructure. The strain rate and temperature sensitivities of the flow stress at low temperatures can be interpreted by the interaction between dislocations and small precipitates. At 1150 degrees C, serrated flow occurs and the deformation has athermal character.