Mechanical properties and low temperature degradation of 1.5Y-1.5Nd-TZP-alumina composites produced by intensive co-milling

Abstract In this study toughness of alumina toughened zirconia (ATZ) was improved by co-stabilization by shifting from co-precipitated yttria stabilized zirconia powder to yttria neodymia co-stabilized starting powders in which the stabilizers were introduced by intensive milling. Alumina contents were varied between 0.5 and 20 ​vol.-%. Test samples were consolidated by hot pressing. Microstructure, phase composition, mechanical properties and LTD were studied. The results show that alumina addition leads to an increase in hardness and to a moderate increase in strength. Decreasing toughness with increasing alumina content is coupled with reduction in transformability. Alumina shows no grain growth inhibiting effect, the grain size is dominated by sintering temperature. An increase of sintering temperature causes a decrease of tetragonality of the zirconia matrix despite a rise of cubic phase content. Samples sintered at 1300 ​°C and 1350 ​°C are extremely ageing resistant while samples sintered at 1400 ​°C irrespective of alumina content exhibit poor LTD performance.