Analysis of non-elastic strain produced in zirconia ceramics

Non-elastic strain behavior was investigated in detail for several different zirconia ceramics (Y-TZP, Y-FSZ, Mg-PSZ and Ce-TZP), and a possible mechanism for anelasticity was discussed. Y2O3-doped zirconia ceramics (Y-TZP and Y-FSZ) exhibited a remarkable degree of anelastic strain, as does Mg-PSZ to a lesser extent. On the other hand, Ce-TZP hardly produced anelastic strain. These results suggest that the anelastic properties depend on the particular dopant additive, irrespective of the crystallographic phase. In Mg-PSZ, besides the anelastic strain, a time-dependent non-recoverable strain is produced under loading. This non-recoverable strain corresponds to the strain caused by a phase transformation. It is suggested that the anelastic properties could be significantly influenced by the level of oxygen vacancy in the matrix, and that the anelastic strain might be produced by a slight shift of ionic species.