IN100 is one of the workhorse nickel-base superalloys of the current fleet of turbine engines owned and operated by the US Air Force. Many of the life-limited locations on fracture critical IN100 components are associated with locations of stress concentrations, e.g. bolt holes, fillets, balance flange scallops, etc. The prior work by Jha, Caton, and others [1-3] examining the fatigue variability of nickel-base superalloys found a link between the minimum fatigue life and fracture mechanics. That is, the minimum fatigue life was predicted assuming immediate crack initiation and growth of a small crack. This prior work only examined the fatigue behavior of smooth fatigue bars. The current effort determined that the link between minimum fatigue life and fracture mechanics is applicable even when only a small volume of the material at the root of a notch is subject to the high stress conditions.

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