Cavity Damage Accumulation in Alumina Doped with Zirconia or Magnesia

For an initial grain size of 1. 0 μm, the accumulation of damage volume in a ZrO₂-dispersed alumina is shown to proceed more slowly than that in a MgO-doped alumina under a given loading condition, irrespective of higher tensile flow stress in the former than in the latter. The slower damage accumulation in the ZrO₂-dispersed alumina is caused from the slower formation snd growth of cavities larger than the initial grain size/ Such slower cavitation is also shown to delay the onset of microcracking. The delayed microcracking leads to higher tensile ductility in the ZrO₂-doped material than in the MgO-doped one.