Effect of alumina addition on the isothermal martensite in zirconia-yttria ceramics by an atomic force microscopy

Surface relief associated with isothermal tetragonal-to-monoclinic phase transformation, i.e., martensitic transformation, in zirconia-3mol yttria (PSZ) with and without alumina addition, which occurred during aging at 130° and 200°C in air or vacuum environment was observed by an atomic force microscopy. The surface relief occurred from grain boundaries into grain interiors as the aging time increased and then spread successively into the surrounding grains with further aging. However, alumina particles and cubic phase particles in PSZ containing alumina acted as obstacles for the advance of transformation, which would be the major reason for the improved mechanical properties of PSZ by the addition of alumina.