Effects of porosity and pore distribution on static strength properties of porous zirconia

Bulk porosity, along with size and spatial distribution of pores, play key roles in strength of porous ceramics, as reported in a study on porous alumina. Hence, a fracture mechanics procedure was proposed to evaluate their strength by presuming that behavior of pore distribution is equivalent to that of crack distribution, and each pore is surrounded by virtual crack. In contrast to alumina, zirconia has distinct spherical-shaped pores. Moreover, its strength properties vary with stabilizing additives. In this research, strength properties of yttria-stabilized zirconia ceramics were studied to verify applicability of the procedure proposed for simulating strength of porous ceramics. The effect of pore characteristics on static strength properties was determined experimentally and confirmed by Monte-Carlo simulations. It was revealed that simulated strength coincided with experimental results within a narrow scatter band, ie, factor of 2(1/2). Therefore, the proposed procedure was found to be appropriate for estimating strength of porous zirconia.