The creep curves of nickel base superalloys are often characterised by a dominant tertiary creep stage due to the accumulation of internal damage not directly related to fracture mechanisms, but rather to a change in the density/mobility of the moving dislocations. A close examination of the experimental creep accelerating stage shows different regimes of strain accumulation depending on the value of the applied stress/temperature. These experimental behaviours can be rationalised by the evolution, during creep, of the reinforcing γ' phase morphology.
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