Damage and Fracture Mechanisms During High‐Temperature Creep in Hot‐Pressed Alumina

The mechanisms responsible for creep damage accumulation and fracture have been examined in two commercial hot‐pressed aluminas. Differences between the two materials can be ascribed to minor compositional variations. Three damage regimes have been identified, depending on stress. However, in all three regimes, failure is controlled by crack propagation. At high stress, a single crack, nucleated at a processing flaw, controls failure. These …