On structural features responsible for the mechanical properties of ceramics from zirconia partially stabilized with Y3+ and Mg2+ ions

It is shown that Y-PSZ ceramics mainly fracture by an intercrystalline mechanism and the gram size fluctuates from 0.2 to 0.8 mum, whereas Mg-PSZ ceramics mainly fracture by a transcrystalline mechanism and the grain size fluctuates from 30 to 80 mum. The high level of mechanical properties is provided by compressive tresses that appear in the transformation of the beta'-phase into the alpha-phase. In the Y-PSZ ceramic, the transformation concerns individual grains, and in the Mg-PSZ ceramics lenticular segregations of the beta'-phase are positioned in the gamma-phase. The transformation is induced by tensile stresses of the elastic field of a crack, i e., can he classified as transformation toughening.