Microstructure and Thermal Stability of Fine-grained (Y, Mg)-PSZ Ceramics with Alumina Additions

Commercial powders within the system Zr02 - Mg0 - Y203-Al203 were used to produce zirconia ceramics with improved thermal stability. Different sintering routes were followed in order to determine the optimum conditions. Fine-grained (Y, Mg)-PSZ ceramics with grain sizes below 10µm were achieved. Microstructural evolution was studied after various isothermalheattreatments.Afterageing.the materials contain a large fraction of tetragonal phase which does not transform after a hydrothermal ageing treatment in an autoclave, but can still be transformed under mechanical stress.