Erosion wear properties of toughened ceramics and composites

Abstract

Erosion wear properties of monoclinic, tetragonal, and cubic zirconia (m-, t-, c-ZrO2 with different fraction of Y2O3 in the range of 2 to 8mol%)/Al2O3 composites and Si3N4 ceramics, were measured by the collision test between the Al2O3 or SiC particles accelerated in air stream (50 ∼ 240m/s) and the stationary target of composites or ceramics. The wear rate of composites increased with increasing the amount of Y2O3 in zirconia. In the case of Al2O3 erodent particles, the wear rate of t-ZrO2/Al2O3 (Y2O3 = 2 or 3 mol%) composites was less than Si3N4 ceramics. The optimum fraction of Y2O3 for wear resistance was 2mol%. However, the wear resistance of all ZrO2/Al2O3 composites for the collision with SiC particles deteriorated. The wear rate of t-ZrO2/Al2O3 (Y2O3 = 2 or 3 mol%) composites reached two times of that of Si3N4 ceramics. Because the impact force acting from Al2O3 particles did not reach the threshold force at which composites undergo the notable damaging mechanism, for example, lateral cracking fracture, the wear resistance of composites increased. However, the impact force from SiC particles was beyond the threshold force of t-ZrO2/Al2O3 (Y2O3= 2 or 3 mol%) composites.