The effect of Mn2+ on the microstructure and mechanical properties of ZrO2 – Al2O3 – SiO2 ceramic materials

In this article, we studied the influence of Mn2+ on the properties (on the phase composition, porosity, microstructure, three-point bending strength and microhardness) and sintering of the ZrO2 – Al2O3 – SiO2 composite ceramic materials. The ZrO2 – Al2O3 – SiO2 ceramic powder containing 2,5 wt.% Al2O3 and 0,5 wt.% SiO2 with 24,7 m2/g specific area was synthesized through co-precipitation method. Three concentrations of Mn2+ are considered: 0.25, 0.50 and 0.75 mol%. The introduction of Mn2+ leads to a significant increase in mechanical properties. The samples sintered at 1250 and 1300 °C for 2 hours. The highest value of strength at three-point bending 761 ± 36 MPa and microhardness 9.5 ± 0.5 GPa was characterized by the material of the composition ZrO2 – Al2O3 – SiO2 containing 0.75 mol.% Mn2+ sintered at 1300 °С. The crack resistance of this material was 7.0 MPa·m1/2. At the same time, the highest values of crack resistance 9.3 ± 0.5 MPa·m1/2 were shown by materials of the composition ZrO2 – Al2O3 – SiO2 containing 0.75 mol. % Mn2+ sintered at 1250 °C.