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

Journal Article · Fri Jul 09 00:00:00 EDT 1999 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(99)00123-8· OSTI ID:6449456

Mercer, C; Soboyejo, A B.O.; Soboyejo, W O ^[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, Journal Name: Acta Materialia Vol. 47:9; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOY-NI53CR19FE19NB5MO3
ALLOYS
ALUMINIUM ADDITIONS
ALUMINIUM ALLOYS
CHROMIUM ALLOYS
CORROSION RESISTANT ALLOYS
CRACK PROPAGATION
CRYSTALS
FATIGUE
FRACTOGRAPHY
FRACTURE MECHANICS
GRAIN BOUNDARIES
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
INCONEL 718
INCONEL ALLOYS
IRON ALLOYS
MATERIALS
MECHANICAL PROPERTIES
MECHANICS
MICROSTRUCTURE
MOLYBDENUM ALLOYS
MONOCRYSTALS
NICKEL ALLOYS
NICKEL BASE ALLOYS
NIOBIUM A
STRESS INTENSITY FACTORS