Strength Properties of Zirconium Ceramics with Silica Additives Hardened with Alumina

Abstract

The effect of Al2O3 and SiO2 admixtures on strength properties of calcia-stabilized zirconia ceramics is studied. Optimal ratios of the components of CaO–ZrO2 + Al2O3 + SiO2 are determined; at these ratios, high flexural and compressive strength limits (σf and σc, respectively) are observed. Their values are the following: σf = 980–70 MPa (at $${{C}_{{{\text{A}}{{{\text{l}}}_{{\text{2}}}}{{{\text{O}}}_{3}}}}}$$ of 5 wt % and $${{C}_{{{\text{Si}}{{{\text{O}}}_{{\text{2}}}}}}}$$ of 0 mol %) and σc = 2.44–0.15 GPa (at $${{C}_{{{\text{A}}{{{\text{l}}}_{{\text{2}}}}{{{\text{O}}}_{3}}}}}$$ of 5 wt % and $${{C}_{{{\text{Si}}{{{\text{O}}}_{{\text{2}}}}}}}$$ of 5 mol %). Signs of plasticity (appearance of a yield line on σ–e diagrams) are observed at the introduction of 4–5% SiO2 in the CaO–ZrO2 + Al2O3 ceramics.