Abstract: After investigated deeply the precipitation of t-ZrO2 particles in ZrO2-6mol%Y2O3 ceramics, it is found that the t-ZrO2 particles in c-ZrO2 matrix precipitated firstly on grain boundaries in the surface layer of the specimen, then on grain boundaries of the inner parts and, finally, within grains of the whole specimen. The particle size varies in the same seguence as their nucleation. T-ZrO2 particles may precipitate not only along [110], direction but in some cases also along [100]. Large t-ZrO2 particles precipitated on grain boundaries transform into m-ZrO2 and is harmful to mechanical properties of the material. Very fine t-ZrO2 Particles precipitated only within grain are beneficial for strengthening and toughening.

Key words: 锆化合物, 力学性能, 陶瓷