Porosity-dependence of elastic moduli and hardness of 3Y-TZP ceramics

The elastic moduli and Vickers hardness of porous 3Y-TZP ceramics have been measured and related to a computed model. At the low porosity level (less than 8%), the spherical model can best represent the effect of porosity on the elastic moduli. As the porosity content increases, the oblate spheroid model needs to be used to interpret the more complex morphology of the porosity and its effect on the elastic moduli. The empirical expressions are also important in a description of the effect of porosity on the elastic moduli. The effect of porosity on hardness is very similar to that on the bulk modulus, which contributes to the body stress, and consequently to the densification taking place beneath the hardness indenter. (C) 1999 Elsevier Science Limited and Techna S.r.l. All rights reserved.