The volume erosion rate of the slip cast monolithic and composite ceramics

Abstract

The volume erosion rate of the slip cast monolithic and composite ceramics was studied using SiO₂ and SiC particles as erodents, under different impact angles (30°, 60°, 90°), at room temperature. Therefore, three groups of samples were prepared: (i) monolithic alumina (Al₂O₃); (ii) composite alumina–zirconia (Al₂O₃–ZrO₂) containing 99 wt-% Al₂O₃ and 1 wt-% ZrO₂ and (iii) composite alumina–zirconia (Al₂O₃–ZrO₂) containing 90 wt-% Al₂O₃ and 10 wt-% ZrO₂. Erosion mechanisms of all prepared ceramic samples were evaluated by the volume erosion rate ( $\omega$ , mm³·g^–1). Obtained results were compared with the analytical Wiederhorn and Evans equations. The mechanical properties (hardness and fracture toughness) of prepared ceramic samples were compared with their $\omega$ under the above-mentioned conditions. It was found that the erosion of monolithic and composite ceramics increased with the increase of the impact angle. Volume erosion rate was highest at an impact angle of 90° and amounts to 115 mm³·g^–1 with SiC, and 12 mm³·g^–1 with SiO₂ erodent particles for monolithic alumina ceramics, 77 mm³·g^–1 with SiC, and 8 mm³·g^–1 with SiO₂ erodent particles for ceramics with the addition of 1 wt-% of ZrO₂, and 61 mm³·g^–1 with SiC, and 7 mm³·g^–1 with SiO₂ erodent particles for ceramics with the addition of 10 wt-% of ZrO₂. Therefore, it can be concluded that the erosion resistance of monolithic Al₂O₃ increases with the increasing amount of ZrO₂ in the composite Al₂O₃-ZrO₂ ceramics, thus erosion resistance can be improved with the addition of ZrO₂.