Behavior of ceramics based on Al2O3 and ZrO2 nanopowders under gamma-ray irradiation

Hardness, fracture strength, wear resistance, and ultimate bending strength of ceramics based on aluminum oxide irradiated with gamma rays (0.8 MeV) up to 2000 Mrad are studied. It is found that mechanical properties of ceramics in which corundum prevails deteriorate under irradiation. Most resistant to gamma irradiation is a ceramic consisting of equal volume fractions of Al 2 O 3 and 2.5 mol % of Y 2 O 3 in ZrO 2 (2.5YSZ) solid solution. A different trend of change in the unit cell parameter of the corundum crystal lattice under increasing irradiation dose is detected: as the irradiation dose increases, the unit cell parameter of the corundum crystal lattice increases in ceramics including zirconium oxide (α-Al 2 O 3 + 10% ZrO 2 ) (ZTA10) and α-Al 2 O 3 + 55% YSZ (ATZ50)), and vice versa, it decreases if there is no zirconium oxide in the composition (Al 2 O 3 , α-Al 2 O 3 + 4% MgAl 2 O 4 (AM1)).