ABSTRACT
This chapter examines the salient microstructural features and mechanical properties of the various partially stabilized zirconia (PSZ) systems, according to stabilizer types, and shows how the properties are influenced by thermal treatment. It describes the general features of PSZ ceramic fabrication and considers these in terms of the various thermal treatment routes. A uniform distribution of precipitates and the prevention of proeutectoid zirconia are most readily attained by rapid undercooling, such that a classical homogeneous nucleation and precipitation process becomes operative. The phenomenon of stabilization of precipitates against coarsening has been considered for metals by Brown et al. and W. C. Johnson. The technique of controlled cooling interrupted by isothermal holds may yield very good strength properties from the “as-fired” condition. Transmission electron microscope observations reveal that the tetragonal precipitate morphology is variable throughout the material, at times appearing like that of Ca-PSZ and at others like Mg-PSZ.
