Mechanisms of fatigue crack initiation and early propagation in cyclically strained nickel superalloy

In the present work, the mechanisms of fatigue crack initiation and early crack propagation of a γ′ strengthened nickel-based superalloy have been investigated. Low cycle fatigue tests have been performed on polycrystalline superalloy MAR-M247 under symmetrical strain controlled loading at ambient temperature in air. The nature of early fatigue damage, crack initiation and subsequent fatigue crack propagation was assessed for applied total...