Ivana Gabelica

The volume erosion rate of the slip cast monolithic and composite ceramics was studied using SiO 2 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 (Al 2 O 3 ); (ii) composite alumina–zirconia (Al 2 O 3 –ZrO 2 ) containing 99 wt-% Al 2 O 3 and 1 wt-% ZrO 2 and (iii) composite alumina–zirconia (Al 2 O 3 –ZrO 2 ) containing 90 wt-% Al 2 O 3 and 10 wt-% ZrO 2 . Erosion mechanisms of all prepared ceramic samples were evaluated by the volume erosion rate ([Formula: see text], mm 3 ·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 [Formula: see text] 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 mm 3 ·g –1 with SiC, and 12 mm 3 ·g –1 with SiO 2 erodent particles for monolithic alumina ceramics, 77 mm 3 ·g –1 with SiC, and 8 mm 3 ·g –1 with SiO 2 erodent particles for ceramics with the addition of 1 wt-% of ZrO 2 , and 61 mm 3 ·g –1 with SiC, and 7 mm 3 ·g –1 with SiO 2 erodent particles for ceramics with the addition of 10 wt-% of ZrO 2 . Therefore, it can be concluded that the erosion resistance of monolithic Al 2 O 3 increases with the increasing amount of ZrO 2 in the composite Al 2 O 3 -ZrO 2 ceramics, thus erosion resistance can be improved with the addition of ZrO 2 .