Hydrothermal stability of mixed stabilised tetragonal (Y, Nd)-ZrO2 ceramics

Yttria + neodymia co-stabilised tetragonal ZrO2 ceramics were developed in an attempt to improve the low temperature degradation resistance of classical Y-TZP ceramics. The influence of the partial substitution of Y3+ by Nd3+ on the phase composition, crystallography, microstructure and mechanical properties was assessed by comparison with 2Y and 3Y-TZP ceramics. Moreover, the hydrothermal stability was tested during 21 h in steam at 200 °C. Although the (Y, Nd)-TZP ceramics are not hydrothermally stable, the phase transformation is limited to the surface region of the material avoiding complete degradation as observed for Y-TZP ceramics. The improved stability is explained in terms of an expanded unit cell parameter and reduced T0 temperature.