Cyclic Fatigue Behavior of an Alumina Ceramic with Crack‐Resistance Characteristics

The behavior under cyclic tension—tension loading of an alumina ceramic with pronounced crack‐bridging (R‐curve) characteristics is studied. Tests on disk specimens with indentation cracks reveal no failures below the static fatigue limit. Theoretical predictions of the stress‐lifetime response, based on the premise that environmentally assisted slow crack growth is the sole factor determining lifetime, are consistent (within experimental scatter) with the data. The results indicate that there is no significant cyclic degradation from potential damage to the bridges, at least in the short‐crack region pertinent to strength properties.