Constitutive modelling and Weibull statistical analysis for the porosity - Mechanical property correlations in 3% yittria-stabilized zirconia system

The study set out to investigate the effect of porosity on the mechanical properties (e.g., hardness and elastic modulus) for a popular structural ceramic composition (as reference), viz., 3% yttria stabilized tetragonal zirconia (3YTZ) depicted the best fit against a second order polynomial decay pattern [equation of the type: M = M0 (1 − c1P + c2P2)]. This is in contrary to the existing models where mostly an exponential decay pattern is noted. The possible reason has been assigned to an error analysis measure (σe) for the goodness of fit of the constitutive equations; a factor not given much importance during in earlier calculations. Weibull data analyses of the modulus and hardness data pointed out that the degradation rate is much higher for specific tests, e.g., compression testing compared to tests on a smaller scale (hardness). The mechanical properties and their rate of degradation were comparable up to the relative density of 70% of the volume fraction of porosity. The decay relationship of mechanical properties is expected to serve as a guide for future modelling and simulation purposes linking other systems, in general.