GRAIN-SIZE DEPENDENCE OF TOUGHNESS AND TRANSFORMABILITY OF 2MOL PERCENT Y-TZP CERAMICS

Fracture behavior was studied for high-quality tetragonal zirconia powders stabilized with yttrium oxide, so-called tetragonal-zirconia polycrystals (Y-TZP). Specimens were prepared from 2 mol % Y-TZP powder. Fracture toughness was determined in four ways from indentation and fracture tests. There is a substantial variation in measured toughness for each grain size, for the material of finest grain size this variation is up to 50% of the lowest value. The trend of the results is that the toughness is strongly dependent on the grain size.