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Title: Micromechanisms of fatigue crack growth in a single crystal Inconel 718 nickel-based superalloy

Journal Article · · Acta Materialia
; ;  [1]
  1. Ohio State Univ., Columbus, OH (United States)

The fatigue crack growth behavior of an experimental, single crystal alloy, of equivalent nominal chemical composition to Inconel 718 is presented. Fracture modes under cyclic loading were determined by scanning electron microscopy. The results of the fractographic analyses are presented on a fracture mechanism map that shows the dependence of the fatigue fracture mechanisms on the maximum stress intensity factor, K[sub max], and the stress intensity factor range, [Delta]K. Crack-tip deformation mechanisms associated with fatigue crack growth were studied using transmission electron microscopy. The relative effects of [Delta]K and K[sub max] on the fatigue crack growth behavior of this material are discussed within the context of a two-parameter crack growth law. The influence of grain boundaries on the fatigue crack growth resistance of materials such as Inconel 718 is also discussed in light of the results of this investigation.

OSTI ID:
6449456
Journal Information:
Acta Materialia, Vol. 47:9; ISSN 1359-6454
Country of Publication:
United States
Language:
English