Apparent and effective creep parameters in single crystals of a nickel base superalloy. I. Incubation period
Direct observation of the dislocation structures in connection with the values of the effective parameters suggests a creep model for that particular creep stage observed in superalloys. The incubation period may be described as a steady state creep rate when deformation is produced by the glide of a low density of mobile screw dislocations (p/sub m/ approximately equal to 10/sup 5/ cm/sup -2/) bowing out between ..gamma..' precipitates. The bowing out rate and hence the creep rate are controlled by the climb of the trailing edge dislocations left at the ..gamma..-..gamma..' interface by the leading screw segment. The effective creep parameters seem to be related to a diffusion process enhanced by pipe diffusion of Ta and Al atoms along dislocation cores.
- Research Organization:
- Ecole Nationale Superieure des Mine, Paris
- OSTI ID:
- 7295282
- Journal Information:
- Acta Metall.; (United States), Journal Name: Acta Metall.; (United States) Vol. 25:7; ISSN AMETA
- Country of Publication:
- United States
- Language:
- English
Similar Records
A model of thermal creep and annealing in finite domains based on coupled dislocation climb and vacancy diffusion
Microstructural creep, fatigue and creep-fatigue modeling of Nickel-based superalloy Inconel 617 at high temperature - 18506