Effect of oxidation kinetics on the near threshold fatigue crack growth behavior of a nickel base superalloy

Journal Article · Sat Sep 01 00:00:00 EDT 1984 · Metall. Trans., A; (United States)

DOI:https://doi.org/10.1007/BF02666360· OSTI ID:5943121

Yuen, J L; Roy, P; Nix, W D

The influence of oxidation kinetics on the near threshold fatigue crack growth behavior of a nickel base precipitation hardened superalloy was studied in air from 427 to 649 C. The tests were conducted at 100 Hz and at load ratios of 0.1 and 0.5. The threshold values of the alternating stress intensity factor were found to increase with temperature. This behavior is attributed to oxide deposits that form on the freshly created fracture surfaces which enhance crack closure. As determined from secondary ion mass spectrometry, the oxide thickness was uniform over the crack length and was of the order of the maximum crack tip opening displacement at threshold. Oxidation kinetics were important in thickening the oxide on the fracture surfaces at elevated temperatures, whereas at room temperature, the oxide deposits at near threshold fatigue crack growth rates and at low load ratios were thickened by an oxide fretting mechanism. The effect of fracture surface roughness-induced crack closure on the near threshold fatigue crack growth behavior is also discussed. 27 references.

• Research Organization: Rockwell International, Canoga Park, CA
• OSTI ID: 5943121
• Journal Information: Metall. Trans., A; (United States), Vol. 15A
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
HEAT RESISTING ALLOYS
CRACK PROPAGATION
NICKEL BASE ALLOYS
AIR
CORROSION FATIGUE
FRACTOGRAPHY
HYDROGEN EMBRITTLEMENT
OXIDATION
REACTION KINETICS
ALLOYS
CHEMICAL REACTIONS
EMBRITTLEMENT
FATIGUE
FLUIDS
GASES
HEAT RESISTANT MATERIALS
KINETICS
MATERIALS
MECHANICAL PROPERTIES
NICKEL ALLOYS
360103* - Metals & Alloys- Mechanical Properties