Abstract
Though a partially stabilized zirconia ceramic shows high resistance to mechanical stress, it has a drawback that the resistance becomes remarkably small when it is held at 200-300°C.
As a result of our investigation for the deterioration mechanism of the ceramic, it was found that the deterioration is due to the great expansion of its volume, which is caused by the martensitic transformation of tetragonal phase to monoclinic symmetry, and it has become apparent that the sizes of tetragonal crystallites which exist in tetragonal grains in the ceramic and the degrees of their strains determine whether the deterioration occurs or not.
