Specific Features of the Behavior of Ceramics Based on ZrO2 with an Admixture of 9 Mole% CeO2 in the Process of Deformation

For zirconia ceramics stabilized with 9 mol.% CeO₂, we study specific features of the processes of deformation and formation of the zones of transformation of the tetragonal phase into the monoclinic phase under the action of mechanical stresses. It is shown that, at room temperature, this transition occurs explosively (autocatalytically) and is accompanied by the formation of large zones of the -phase in the form of strips on the surface of tension of the specimen and the appearance of a nonlinear sawtooth section in the stress–strain diagram. As the testing temperature increases, the degree of autocatalyticity decreases together with the degree of nonlinearity and the diagrams lose their sawtooth character. At the same time, the strength of the material becomes almost four times higher at ~ 200°C and then decreases to the initial level at 400°C. It is assumed that this Type of mechanical behavior can be explained by changes in the mechanisms of hardening of ceramics.