Modelling of recovery controlled creep in nickel-base superalloy single crystals

Journal Article · Wed Jan 01 00:00:00 EST 1997 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(96)00151-6· OSTI ID:445329

Svoboda, J; Lukas, P ^[1]

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1. Academy of Sciences of the Czech Republic, Brno (Czech Republic). Inst. of Physics of Materials

A model of the kinetics of recovery controlled creep in {l_angle}001{r_angle} oriented nickel-base superalloy single crystals has been developed. Two basic deformation mechanisms have been considered, namely (1) deformation of {gamma} channels by slip in discrete slip systems connected with the generation of dislocations and their deposition at the {gamma}/{gamma}{prime} interfaces; and (2) dynamic recovery of the dislocation structure due to non-conservative motion (a combination of slip and climb) of dislocations along the {gamma}/{gamma}{prime} interfaces and their annihilation. The climb of dislocations is conditioned by the diffusive transport of vacancies generated and annihilated at the climbing dislocations. In the steady-state creep the rate of the slip deformation in all the {gamma} channels is in equilibrium with the recovery induced diffusional deformation. The model predicts realistic values of the steady-state creep rates and their dependence on the applied stress, as well as the strains corresponding to the end of the primary creep stage, dislocation densities at the {gamma}/{gamma}{prime} interfaces and resolved shear stresses both in the {gamma} channels and in the {gamma}{prime} particles.

• OSTI ID: 445329
• Journal Information: Acta Materialia, Vol. 45, Issue 1; Other Information: PBD: Jan 1997
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
33 ADVANCED PROPULSION SYSTEMS
NICKEL BASE ALLOYS
TURBINE BLADES
CREEP
MATHEMATICAL MODELS
KINETICS
SLIP
DISLOCATIONS
VACANCIES
STRESSES
STRAINS