PLASTIC DEFORMATION OF CUBIC ZIRCONIA AT TEMPERATURES BETWEEN 1150 AND 700℃

摘要

The plastic deformation of cubic ZrO_2 single crystals containing 11 mol.% Y_2O_3, which were considered to be brittle below about 1100℃, was studied in compression along [112] between 700 and 1150℃. Single slip was observed on a (001)[110] 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℃, serrated flow occurs and the deformation has athermal character.