Multiscale modelling of the thermoelastic properties of alumina-zirconia ceramics for 3D printing

Abstract

Additive manufacturing appears to facilitate the accurate manufacturing of alumina-zirconia technical ceramics. Nevertheless, the fine tuning of the manufacturing of these components by 3D printing requires an analysis of the parameters that influence their final thermoelastic properties. In this context, this work presents the application of (finite element-based) numerical procedures that aim at the prediction of the effective thermoelastic properties of 3D-printed alumina-zirconia ceramics. The numerical modelling considers three different scales: micro-, meso- and macroscale. The microscale corresponds to the microstructural level of, sintered at 1500 ºC, slip-casted samples with different compositions of alumina-zirconia. On the other hand, the macroscale corresponds to the macrostructural level of porous lattice of 3D-printed ceramics, being defined at the mesoscale level by a periodic unit cell. Thus, an initial microstructural analysis (at microscale level) provides the influence of the alumina/zirconia ratio on the (macroscopically homogeneous and isotropic) material thermoelastic properties, which together with the definition of the geometry of a periodic unit cell (at mesoscale level), provides, by a second analysis (at both the meso- and macroscale levels), the coupled influence of material and geometry of the macrostructural lattice on the structural (macroscopically heterogeneous and anisotropic) thermoelastic properties. Moreover, experimental thermoelastic properties of the sintered slip-casted specimens were obtained for several alumina/zirconia ratios and analyzed together with microstructure patterns. Prediction of the microstructural effective thermoelastic properties was also made using micromechanics and composite theory (analytical) models. All the numerical, experimental and analytical results for the microstructural level are presented and compared. Numerical results for the meso- and macrostructural levels are also presented.