The Modeling of the Fracture of Three-Phase Ceramic Composite

Abstract

In the present study, elastic and strength properties of three-phase Al2O3–ZrB2–SiC composite are investigated based on numerical modeling. Representative volume element (RVE) consisting of Al2O3 matrix, pores, and ZrB2 and SiC inclusions is built based on the experimental data. The uniaxial tension loading of the RVE model under plane strain conditions is considered. The relations of an isotropic elastic-plastic medium with the Drucker–Prager yield criterion are used as constitutive equations. The determination of the effective mechanical properties of the composite is based on the analysis of numerical averaged stress-strain curves. The simulation results demonstrate that the cracks nucleate in the regions of high stress concentration caused by the pore shape. The alumina matrix fractures due to the criterion based on the tensile pressure, while the fracture of inclusions occurs when the criterion based on the accumulated inelastic strain is fulfilled. The influence of the fraction of SiC inclusions on the effective elastic properties of the composite material was studied. It was shown that the elastic moduli weakly depend on the increase of SiC volume fraction in the considered range from 0 % to 34 %.