Creep deformation in a 3 mol% Y2O3-stabilized tetragonal zirconia

The high temperature deformation behavior of a 3 mol% yttria-stabilized tetragonal zirconia (3Y-TZP) is examined. The analysis of creep strain rate, which was monitored directly with an optical extensometer and corrected for the current grain size, reveals a sigmoidal feature in the true stress-creep rate relationship. At lower stresses, a stress exponent n of ∼1.6 incorporated with a grain size exponent of 2.0 suggests the intervention of a lattice diffusion creep mechanism. For higher stresses where n ∼ 2.7, evidence of intragranular dislocation activities suggests that dislocations may play an important role in the accommodation process for grain boundary sliding in 3Y-TZP