Compositional Effects on Mechanical Performance of Zirconia–Magnesia–Alumina Ceramics

The study of the relationship between the composition and mechanical properties of structural ceramics based on zirconium, magnesium and aluminum oxides is an important scientific and technological task. In this study, ceramics of the composition x·ZrO2-(90-x)·MgO-10·Al2O3 (x = 10–80 wt.%) were obtained using standard ceramic technology. XRD, SEM, Vickers hardness and biaxial flexural strength measurements were performed to determine the effect of concentration x on the phase composition, microstructure and mechanical characteristics of the sintered samples. The results show that with an increase in the starting concentration x in experimental samples, the fraction of the stabilized ZrO2 phase grows, and the grain size decreases. These two factors determine the values of microhardness and biaxial bending strength. Experimental investigation on the ternary oxide ceramics shows that for ceramics sintered at 1500 °C, the microhardness values varied within the range of 815–1300 HV1 and the biaxial bending strength of 110–250 MPa.